How to solve multiple maths operation using Digital roots

Hello all, I have a question. (560 / 32 )x (720 / 48 )= ? a) 262.5 b) 255 c)  263.5 d) 271.25 Is there any way to get correct answer using any shortcut or digital roots? I want to do it fast Thanks

Topic by abharti 7 years ago  |  last reply 7 years ago


The Square Root of NET?

What is the square root of the internet?

Topic by RelyNupon 11 years ago  |  last reply 8 years ago


Experiment: Use of Hydrogen Peroxide to induce root formation in plant cuttings

I decided to try an experiment to see if dilute concentrations of hydrogen peroxide could promote root formation in cuttings. A rack of twenty test tubes was set up in the first distilled water the second a 1/100 solution of 3% h2o2 third 1/50 solution of 3% h2o2 fourth 1/25 solution of 3% h2o2 and fifth 1/12.5 solution of 3%h2o2 We see in this image taken after one week that only the control has started growing roots. Conclusion, H2O2 does not induce rooting of cuttings.

Topic by Tool Using Animal 10 years ago  |  last reply 8 years ago


What is the safest way to trim a bonsai tree's roots without hurting it?

Question by LawnBoy1991 10 years ago  |  last reply 8 years ago


How to root woody viburnum.

I have a favorite viburnum that I'd like to root. I've used rooting powder and loose soil but I haven't succeded. Can this plant be rooted from a cutting?Thanks,Tim?

Question by x7c00 7 years ago  |  last reply 7 years ago


what is the square root of Pi? Answered

 

Question by bendog38 9 years ago  |  last reply 9 years ago


What is the square root of -2? Answered

 I need to prove my math teacher wrong

Question by bendog38 9 years ago  |  last reply 9 years ago


Hi3516 Access Root Error

First, I apologize for my english. I have a camera module with hi3516 SoC and have to access to hi3516 as root. But I couldn't that. If I begin to explain from start. I had an IPC, extracted it and now I have 3 modules (camera module, ir cut module and power / api module). I found 3 holes on camera module, these are GND, Rx and Tx. I soldered them with 3 female jumper cables and connect to ftdi module. I used micro USB to USB for ftdi-pc connection. Powered up camera module with 12V. In while, I download a program, what name is coolterm, to my pc. I opened coolterm and set baud rate to 115200 (hi3516 standard). Camera module booted up. I pressed a button when I see "Hit any key to stop autoboot: 1" text. Until here I followed an article and everything is fine. But that article says "You have to press enter after to type "root" to gain shell access" and I can't access shell when type "root". I got an error like "Unknown command 'root' - try 'help'". Hi3516 has embedded linux os. Article Link: https://felipe.astroza.cl/hacking-hi3518-based-ip-camera/ Any ideas to help me?

Topic by Anıl Enis 1 year ago


Is there a particular season for ginger root?

I was grocery shopping... one place (a Walmart Neighborhood Market) did not have any ginger (they did about two months ago). The next place (Publix -- a large supermarket chain in the south east) had some, but most of it was moldy and disgusting (surprising because Publix tends to keep very high standards). Just curious if there's a reason why I can't find any. I'm looking to experiment with homemade ginger ale - I had some in a restaurant, so I want to do some testing to come up with a similar recipe :D

Topic by trebuchet03 12 years ago  |  last reply 12 years ago


which plants provide root stimulating hormons and how are they extracted?

Question by systex 10 years ago  |  last reply 10 years ago


is it safe to root my mobile phone? Answered

Hey everybody, I'd like to root my mobile phone, I have a Galaxy Gio and want to get some more out of it. I know it is simple to do, but does anybody know if it is safe?

Question by lukeD 6 years ago  |  last reply 6 years ago


Pandigital Novel Anriod Root Instuctions

Looking for instructions to unlock andriod front end on this device

Topic by broncfan1968 7 years ago


how to "ROOT" samsung intercept for sprint Answered

1)     how do i "ROOT" my samsung intercept from sprint? i found a few apps that are amazing     ("wifi tethering", "set CPU", "root explorer" "root manager"), but  i need superuser (root)     access. can anyone explain what "ROOT" is and how to get it?     (update) I'm starting to understand "ROOT" is.) 2)      and what is  "KERNAL" 3)      i want to install flash player 10.1 on my intercept from sprint, but after i installed, it was the      same. do i have to root my phone? 4)     i cant find any good info on HOW to root the SPRINT INTERCEPT phone. 5)     which is better, the samsung moment, or the samsung intercept? 6)     is this the ONLY phone the SUCKS in EVERY SENSE (bad screen re;  unable to root;  no     multi-touch; android 2.1;  no flash support;  non-sensitive capacitive buttons;       unresponsive;  slow) 7)     (update), my phone updated today and now is running 2.2, froyo. now the capacitive      buttons work the way there supposed too. but i still cant i update flash.  and is rooting      gonna be possible (or at lest possible)? (re update 2011 Jan. 11) my phone still has no multi-touch (except for the "pinch to zoom" like before.but only on the browser); no flash player; and the hardware still SUCKS (bad res LCD screen, "EV-rev O" radio, ABSOLUTELY TERRIBLE built in memory) some reason this phone after the 2.2 update, is a LOT slower and more unresponsive then before. 8) does anyone know how to root this phone and flash it with some better-suited software for this model phone (m910)

Question by -max- 8 years ago  |  last reply 7 years ago


How can I scan to roots of plant that inside of the pot?

Dear friends, I am an academician in Faculty of Agriculture. Roots development of plants is an important parameter in our experiments. So I need to display the root length without remove the plants from the pots. I need to find the differences between cultivars or treatments about root length, efficient root depth and root area. If I can display it similar to example images, so if I can distinguish the roots by photoshop, It will be so useful for me. Is there any sensor, method or such thing that I can scan the roots without the damage the plants by using of arduino ? or any DIY device. Coloring is not important for me, I need just selection of roots. Best regards.

Question by JeoleX 2 years ago  |  last reply 2 years ago


How can i build a inexspensive root celler ?

Question by dhegg5 10 years ago  |  last reply 10 years ago


easiest way to root and tether an samsung galaxy s?

Question by aschutters 7 years ago  |  last reply 7 years ago


Root Beer - Is there any way I can make a root beer beverage from scratch?

I am in a place that does not sell Root Beer or the syrup to make it so I want to try to make it on my own.  Any suggestions?

Question by rosey gillespie 7 years ago  |  last reply 7 years ago


Does anybody know about hair root removal?

Does anybody know about hair root removal?

Question by poch 9 years ago  |  last reply 6 years ago


How to reset root password of Huawei MA5683T?

Hi,everyone!Is anyone here good at networking? I have lost the root password of my Huawei MA5683T, I want to know how to reset the root password or get it back?

Topic by I3I1996 1 year ago  |  last reply 1 year ago


Rooted Nexus 7 maxing out cpu

I've had my Nexus 7 rooted for several days now, mainly for the use of multitouch gestures that I so loved on the ipad, and in that time my battery life has been terrible! I have found that there is only a few more processes running on the device (gmd gesture control and SuperSU) which are of course supposed to be there, but they seem to be maxing out my CPU  Every app I have used to monitor CPU usage (rooted or no) have all said my CPU is at 100% all of the time. After a lot of googling around I have still yet to find anyone saying anything about being rooted maxing out anyones CPU. My question is, Is there any way I can stop root access from eating my cores and my battery?

Question by Laserman595 6 years ago  |  last reply 6 years ago


What is the best way to roast dandelion root to be used as a coffee substitute? Answered

I found an article on the web touting dandelion tea (brewed dried root) but also saw that it was a better taste if roasted and used instead as ,  but in place of coffee ! Is there a specific method of roasting the roots ?  Dry and crispy or all but burnt ?  Anybody know?

Question by gearhead1951 6 years ago  |  last reply 6 years ago


compost pile full of roots How do I stop this from happing?

Last fall I cut up a pile of leaves about 3 feet high. In the spring I added grass and kitchen scraps. when I tried to turn the pile it was so full of roots that I could not turn it over. I am unable to use it because these roots are so small and intertwined it is useless. how do I stop the roots?

Question by 9 years ago  |  last reply 6 years ago


How do you do a square root in Windows Calculator when in scientific mode?

Is it just me, or is it impossible to do a square root in Windows calculator when you got it in scientific mode?

Question by doctasnowman 9 years ago  |  last reply 2 years ago


My Garden is full of roots from a tree next door. Is there any way to get worms back into the garden?

 My garden is full of roots from a tree. What ways can i get the dirt back?

Question by hoihoi151 9 years ago  |  last reply 7 years ago


Will an update for/ or rooting my phone will enable mhl support?

Hello everybody! I just bought a mhl cable for my mobile phone, but after connecting it, my tv doesn't show me anything. I searched my phone spec's and I found out that my phone doesn't support mhl. Such a shame! But then I was wondering, my phone runs on android jellybean. If I upgrade it to android KitKat, would I then be able to use the cable? Or should I just root my phone? (Does any of you have a good rom for me that supports mhl?) I have searched a couple of hours on google but it didn't gave me some answers. I hope you guys can help me. My phone is a Samsung Galaxy S4 mini (GT9195) with jellybean on it.           

Question by lukeD 4 years ago  |  last reply 4 years ago


Warning, a new and nasty root kit going around

Be sure to make your backups, Microsoft says the only way to fix this one is a reinstall. http://www.computerworld.com/s/article/9217953/Rootkit_infection_requires_Windows_reinstall_says_Microsoft?source=CTWNLE_nlt_pm_2011-06-27 However there is a lot of discussion and some say its fixable. Either way its another pain.

Topic by Vyger 7 years ago  |  last reply 7 years ago


The future of mobile operating system or the end for "hackers" and rooting?

For mayn years it was almost logical to get full root access on your new smartphone or tablet.The other fraction might now it as "jailbreaking"...No one really needs it unless they are not happy with they way the mnufacturer designed the operating system and features.The removal of bloat, apps the user never needs, is still the most common reason for rooting.Custom ROM's offering a different experience are right behind.Now we also have TV's, entertainment boxes of all kinds, even from our ISP's directly.The main provider for the operating system is now Google with only a few "competitors" left.Apple has a strong hold of the mobile and tablet sector too but is not really presented in other areas.Android is still open source but Google heavily modifed it to suit the needs of data collecting and security for features like banking, access control and so on.What is good for the normal user and perfect for those with security in mind can be really bad for those actually just using a device.No matter why you buy a new phone from your provider, you almost never buy it for the added apps and services.Rooting has become more and more difficult.One reason of course is constant security updates and removing possible access options for even simple things like getting USB debugging and an unlocked bootloader.People dedicated to find ways to remove provider locks, creating custom firmwares or the basic tools required to work with firmwares were called hackers.If you buy a new car and decide to modify it with a new engine, seats or whatever than no one will stop you.So why don't we have the same rights for our electronic companions?I wouldn't call it hacking, I would call it actually owning and controlling your device instead of Google letting control you - or Apple, but who cares....The other reason is dead simple: Those guys who started it all have retired or found employoment with those they fooled for so many years.Chainfire should ring a bell for anyone ever concerned with rooting.The master is gone now and only a few people are willing to take his legacy.For Asian devices the community over there is better off but for our market region right now Magisk seems to be the only option left for modern devices.The sneaky ways to lock us out....Security comes at a price, simple as.You can offer secrity for money transfers if the device is not trustworthy.Same for online streaming - you want the money for what you give and prevent that someone is able to make unwanted recordings without encryption.The list goes on with access control system and literally everything we use our devices for that involves some security.Even with the lates PIE systems Google's own devices are still quite friendly in terms of gaining root access.Different story though if a manufacturer makes full use of all the latest addition at Google's disposal.Device security no longer starts with the boot we see.It is now possible to create a hardware based tree of trust.This means any modification to anything will cause a failure.This locks out all "tools" able to read out partitions and vital data while a device is in fastboot mode.And of course said fastboot can be fully disabled as well now.For security reason a so called A/B configuration is used.Updates come over the air and are applied to the dormant system.Next start will boot the new system and then update the old one, no requirement to manually apply and update.The recovery can also be abandoned and replaced by a system using a copy on the device itself that is updated through OTA updates with the firmware.So both ways to gain official access can be full removed from the user.From there we get encryption, hash checks and literally everything working in its own user space - a full SELinux enviroment at the highest level.There are already devices utilising a lot of this and so far the only way to get any sort of insight was done by those intercepting OTA updates on a router level.And apart from quickly changing the encryption with the next updates nothing was gained.Is it all coincidence?Of course not.Well known leaks were kept open for years.Kernel updates gave improvements and closed really old leaks but never all known ways.With the retirement of the best rooting experts these holes were suddenly closed.Checks of latest kernel releases showed that there is no known vulenerabilities anymore that can be misused to gain access.And those finding new ones and making them available for us are bascally gone now.Encryptions and packing algorithms changed, same thing for the actual handling of partitions and rights.Anyone with a decent understanding of how the old ways worked will be able to figure it out with some time wasted on it.From there however the outcome is often dark.The tools needed to work with these new files are not always updated anymore.The developer simply moved on and most of the time without publishing his source codes.And the still best way to protect your firmware from tampering is to encrypt it.In the old days it was enough to sign a ZIP file with a release key not available to the public.Custom recoveries allowed us to get around this.This still works to some extent but now we also get additional checks starting from the bootloader.A modified system will be detected and stopped and a stock system will stop i a modified boot is detected.Even using a custom recovery by flashing or through fastboot is preventable now.Right now the only way for most new devices is a total wipe and the installation of an unsecure firmware with everything.As you already guessed this is to prevent now as well.So does all this rooting stuff actually concern you?Of course not!If you never had any need for rooting or no clue what to do differently with a rooted device than you are a happy camper.But your neighbour or friend might think differently.You see, I have two problems when it comes to "stock" devices.a) I have no clue what data they collect from me and what it might be used for.b) I do not like being forced to agree to terms that are endless and of questionable content just to use the damn thing.For crying out loud: In most cases it is now impossible to even set up a new device without working internet and a Google account.....

Topic by Downunder35m 4 months ago



Not needing root access to mount drives?

I have been using sshfs (mounting SFTP servers) with MacFUSE on my Mac Mini (Snow Leopard). When I mount an SSH server, I can do it without having to be root, and i'm fine. My friend, on the other hand, tries to mount my SSH server, and it says access denied. He then runs the mount as root and it works fine. The issue with running as root though, makes it not accessible by Finder. He's an administrator on his computer (which is Snow Leopard on a MacBook (White)). How can he mount it as himself (his account)?

Question by conradev 9 years ago  |  last reply 9 years ago



Project Ideas that use a 5 liter Root Beer Keg?

So a few years back, i got a Virgil's Root Beer 5L Party Keg for Christmas. I didn't get much use out of the drink, but once it was emptied, i removed the plastic bits on the top and lower sides. Now its just and empty, small keg roughly the size of a 1 gallon milk jug but in barrel form. Does anyone have any ideas for what i could do with it? Cuz i got nuthin right now.

Topic by EngineerJakit 4 years ago  |  last reply 4 years ago


is it possible to root my sam-sung intercept (sprint) with the froyo update? and what about flash player? [answered]

Is it possible to root my samsung intercept (sprint) with the froyo update? what really pisses me off about this phone is that it has NO flash player at all. ive tried installing it from the adobe website, Googleing "flash plater 10 for 2.1", and looked throughout the market. its not there (i thought it is there for 2.2 froyo but NOOOO this phone has to be horrible). also moved the app from "downloads" to "tunnybrowser> app_plugins" nothing works any suggestions? can anyone offer me some simple rooting and flashing this phone? also, will writing a sudo command in the "ROOT" folder work? it seems like i can. using this phone it so far seems i can "create" a folder in the ROOT folder. will this work or will it brick my phone? using some apps from the market, i discovered my phones CPU does not go higher than 199MHz. this REALLY UNPLEASANTLY PISSED ME OFF. NO WONDER WHY MY PHONE IS SO DAMN SLOW! how do i increase it to the 800MHz it was rated for? and what would happen if i tried to over-clock it to 1 ghz?

Question by -max- 8 years ago  |  last reply 7 years ago


Can a bamboo plant and an Apple Snail coexist?

I'm thinking about putting one of my extra Bamboo plants in my Apple Snail's aquarium, any thoughts? My main concern is fertilizer on the roots being harmful to the snail. Would rinsing off the roots be enough?

Question by action_owl 9 years ago  |  last reply 8 years ago


Will I still be able to make calls if I install a custom ROM on my EVO 4G?

I want to root my EVO 4G for WiFi tethering and to install custom ROMs.. Will I still be able to make calls even though I will flash a custom ROM?

Question by ladygaga 8 years ago  |  last reply 8 years ago


How To Fix The World & Grassroots Innovation Takes Root - Instructables in Forbes

Instructables, Squid Labs, Saul, and Eric are all in Forbes:Grassroots Innovation Takes Rootby Peter HoyThe next great wave of technology maybe something that you invent yourself. Really.Most of the big commercial technology companies do all they can to hide the complexity of their products under shiny tamper-proof surfaces. They believe consumers don't want to read manuals. The fewer buttons the better. Think Apple, automakers and most consumer electronics makers.But there's a subversive movement building, too, led by self-proclaimed do-it-youselfers. They want to reinvent the gadgets in their life, much like software hackers have reworked code. They don't all have expert technical skills, but they have a passionate desire to reshape technology in their own rough image.What makes their dreams possible is easy access to open-source software, cheap microchips and wide-open collaboration on the Web. It's the manufacturing-sector version of desktop publishing.How To Fix The World by Quentin HardySaul Griffith (above) is only 34 years old, but he's already helped create enough technologies and companies to last a lifetime. A short list includes a cheap way to prescribe and create corrective lenses in the developing world, a wind energy generation system using massive high-altitude kites and a human-powered energy project.His greatest creations, however, may be a popular comic book series called HowToons, designed to help kids think like inventors and, with Massachusetts Institute of Technology pal Eric Wilhelm, a Web site called Instructables, created to spur collaborative invention among adults. More news and press about Instructables here.

Topic by ewilhelm 10 years ago  |  last reply 10 years ago


How to rip data from a phone?

So my phone is now rather broken, im using a backup as a large portion of the touchscreen is no longer responsive, so my issue is that there are large amounts of data i would prefer not to lose on the phone in various apps and things that would not be saved to the sd card for instance the messenging service Kik, i have a lot of messages i would prefer not to lose  ive always thought when i wouldnt have an issue with a root going bad , for instance when i would have a replacement phone on hand, then i would root it and get the data off it so my issue comes down to is it possible to root a phone, retrieve the data WITHOUT needing the fully functioning touchscreen? for instance all through the computer  the phone's model is the T-Mobile MyTouch Q (without slide out keyboard)

Question by JakeWhelchel 4 years ago  |  last reply 4 years ago



Cleaning a Saitek Cyborg Keyboard? Answered

I spilled a root beer float in my Saitek cyborg keyboard, which resulted in sticky keys everywhere. I rinsed it under water once and now all the keys work fine, except the '2' and 'X' keys. How can I clean these two without risking damage to my keyboard?

Question by The Daft 9 years ago  |  last reply 9 years ago


Can someone help me with a step by step to allow Jasper to control GPIO pins?

I have Jasper up and running and have created a couple of basic speech modules but i cannot find out how to get it to use a module that needs root permission. i have read about import os but i do not know how to use it. Any help would be great.

Question by WilliamP6 4 years ago


Hate is fear, and fear is rot. That cankers root and fruit alike-Robert Graves

An interesting thing happened this morning, I normally get up a couple of hours before my wife, it gives me time to study and think. Well, this morning, about 7:30, I'm comfortable in a chair and a half by the front window, drinking my coffee and studying fluid mechanics for a test Monday when a car stops out front. I don't think much of it, then I hear the car door and I'm thinking "Great, they want to sell me something". But no, much to my incredulity, I hear spew forth a vitriolic stream of profanity and epithets directed at the campaign sign in my front yard. Now I'm not given to either panic or rage, and the door is still locked, so my response is more one of bemusement than anything. But later it occurred to me, regardless of any outcome come November, America is a deeply wounded and divided nation. How very sad.

Topic by Tool Using Animal 10 years ago  |  last reply 10 years ago


I have multi-store website in magento, i want script when we pass alias or parameter then make folder in magento root?

I describe here in full view:- step 1: alias or parameter is "abc" now it display in magento website like "abc.site.com" // it is done by me no issue here i allready done in mywebsite Step 2: Now tha main content here  I face problem here right now:- I want script which is available in root of magento when alias or parameter pass then make folder "abc" in root of magento and two files index.php & .htaccess inside the "abc" folder. so please if any body have the any idea on step 2 please  share the code with me.

Question by praveenpal 5 years ago


Please explain Theo Jansen Mechanism?

We all have seen the Theo Jansen Machines and they are JUST AWESOME! I'm trying to build one. What is the the theory and mechanism behind Jansen's machines? Please explain. [Unicode Symbols for your convenience: Degree= ° , Half = ½ , Third = â��, Fourth = ¼, Three Fourth = ¾ , Integral = ∫ , Differential = ∂, Delta = Δ , Square = ² , Cube = ³ , Square root = √, Cube Root = â��, Infinity = ∞, sum = ∑ , Therefore = ∴, Because = â�µ,]

Question by sarveshk 7 years ago  |  last reply 6 years ago


Can someone help me with my Veeder-Root electro-mechanical counter reset solenoid ?

I have an old Veeder-Root electro-mechanical counter.   The counter works on 12V but the solenoid for reset seems to need a totally different voltage.  I have gone up to 24v DC which is as high any of my power supply equipment can go with no luck.   In desperation I tried to throw 120VAC to it and it buzzes so I am thinking it needs 120VDC but I am not 100% sure the best and easiest way to get it there.  I am guessing some sort of bridge rectifier, any thoughts or ideas?  I am working on a sculpture that counting is part of the look but I would love to have a pushbutton control to reset the counter. There is no model number but the Form NO is 1 159196  ELC    12V DC

Question by CharlesR88 2 years ago  |  last reply 2 years ago


Aeroponics

I hope my mom doesn't see this, its going to be her birthday gift hopefully ;D. I was looking around instructables for good projects for my garden-loving and food-growing mom, and noticed several hydroponic systems. They all looked nice, but I noticed one thing: they all used the nutrient-film or submerged plant technique. I'm no expert, but this seemed bad for the roots. Rot, anyone? I recalled a system I had seen at Walt Disney World in the distant past (OK, 4 years ago :P), where plants roots passed through a nutrient-laden mist. This seemed a better solution to me, allowing the best nature of hydroponics to take root (no pun intended lol): supplying the roots with nutrients while allowing them to breathe and supporting them. I thought about how to create the mist and it hit me: a hose sprayer. Most sprayers nowadays come with an adjuster nozzle to change the flow, so if one were to move it to "mist" position, tape down the handle and attach it to a large submersible pump on a timer, you have a cheap aeroponics system. I'll be writing an instructable when I can, so stay tuned for updates.

Topic by Rotten194 10 years ago  |  last reply 8 years ago


Keeping the environment moist or damp

I'm building an aeroponics system from scratch. When I water my roots in bursts of 3 to 5 minutes how can I be sure that the environment stays moist while I am away, I don't want the roots on my capsicum annuum to dry out. Is there anything I can line my 4" PVC tube with to keep it damp inside but without using soil or any geological material or perhaps and organic material that wont damage the cycle? Is this what aggregate is used for?

Topic by bprins 4 years ago  |  last reply 3 years ago


Propagating a spruce tree

I have a Norway Spruce tree about 20 years old, but too young to bear seed cones. what is the best way to propagate from cuttings?

Topic by 10joey 7 years ago  |  last reply 7 years ago


Can I substitute a Standard Acoustic Guitar for an Acoustic Bass/Bass with Amp? Answered

I may be playing an acoustic set with my band at a local concert/festival, I play Bass, and it being an acoustic set, I don't think I will have access to an amp, and I do not have access to an acoustic Bass. Would it be practical to play the root bass notes, as power chords on a standard Acoustic guitar? I understand that the question has a lot of variables, but does anyone have any experience of this type of situation?

Question by cosgrove 9 years ago  |  last reply 4 years ago


Groasis helps trees grow anywhere

Want to plant trees anywhere, even the desert? Then the Graosis Waterboxx might be the solution. It's a container that sits around the base of a young tree. It collects both rainwater and condensation in a reservoir and the water is then wicked down to the roots. Once the tree's roots grow down deep enough to sustain itself, the box can be removed. It seems to be pretty effective, too. While testing in the Sahara desert, 90% of trees that used the Growboxx survived compared to only 10% of the other trees that were planted and watered daily. The next step is to test at 25 locations in 8 different countries.

Topic by fungus amungus 9 years ago


Can anyone explain RMS vs average? (particularly the math portion, and the intuition)? Answered

My current understanding of RMS (Root Mean Square) is that it is the equivalent AC voltage/current/power necessary to drive a resistive load the same around as the DC voltage/current/power counterpart. However, I am a bit confused about the math involved that can apply to all waveform. I know the conversation factor for sine waves is 1/ sqrt(2), and that the conversion factor for square waves is 1:1 (no difference) On my graphing calculator, if I take the square root of the definite integral (from 0 to pi, integrating the x ) of the sin(x)^2, then divide that by the period, pi, I get the correct answer. However, what is the purpose of the squaring, then square-rooting? is it purely to perform a absolute value mathematically? If so, then I should be able to simply integrate the absolute value of the sine, and divide the result the the period the integration was performed over. If it period it was performed over was 0-pi, then there is no need to even take the absolute value! But this method returnees 0.636619... not 0.707106... Intuitively, it makes much more sense to me to somehow take the mean average of the continues |sin(x)| function. I know this can be done with desecrate numbers (a sequence, perhaps) and by taking the sum of them, and dividing it by the number of 'elements.' (series's, anyone?). I would expect this average is what determined the average power used by a load. EDIT: Wikipedia states that "The true RMS value is actually proportional to the square-root of the average of the square of the curve, and not to the average of the absolute value of the curve." So it appears I have just proven this. But Why???? What is so special about the squaring and rooting??? Please don't bombard me with heavy math, as I am not familiar with calculus, and have barely passed pre-calculus (The class was supposed to touch upon series and sequences, and integrals, derivatives, limits, etc. but due to show days and delays, the class only covered trigonometry --the bare essentials--). I do not yet fully understand single-variable integrals, let alone multi-variable calculus. I really just want a better intuition of RMS. More than likely, there is probably some confusion I have about integrals in general, and how to calculate them on-paper.

Question by -max- 4 years ago  |  last reply 4 years ago


Sawdust as a medium for hydroponics? Answered

Actually I have 2 questions pertaining to hydroponics. First you should know that I have a passive hydroponic system functioning right now the container is partially submerged in a nutrient solution with holes in the bottom of the container. The medium I'm using right now is perlite to allow more oxygen and act like a wick. I do have a top layer of aquarium gravel to anchor the plant better. I've been thinking of trying to add more oxygen to the roots by using an air pump. I was going to insert the tube from the top (the dry section above the water) pointing down to the wet section to blow some air to the roots. Would this be an unnecessary addition if I continue to use perlite as a medium? My second question is the title, would sawdust work as a medium for hydroponics? I assume it would be able to act like a wick for a passive system my concern is would the roots get enough oxygen in sawdust? Also most mediums are inert sawdust wouldn't be, would that have a negative impact on my plant?

Question by thecoonskin 6 years ago  |  last reply 6 years ago