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# What is the square root of -2? Answered

I need to prove my math teacher wrong

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Square root (-2) = 1.41421356 i

-2 does not have a 'rational" sqrt because -2 is not factor able in a sqrt.. The answer below would be sufficient in a calculus class because you factor non-real numbers in there.
2 also does not have a rational sqrt. The way you can see this is hit the sqrt button on your calculator after -2. You come up with a decimal which is the non-rational calculus answer. If you are in Algebra 2 like me, make sure to call it non-real. I hope that helps

Why is your math teacher wrong by the way ?

Most of us 9th graders at North Canyon HS are right about math questions and like to make argue over just about everything.

as a freshman you should be quite and try to listen to your math teacher. believe it or not he (or she) is pretty smart, probably smarter than you. show some respect, teachers are underpaid, under appreciated, and esential to society.

P.S. sorry about the mini rant

sorry I meant quiet not quite

Dude, mini-rant's fine, but you have good advice.

Ha, we did that in school as a stall tactic.

In retrospect, it was a stupid thing to do, and I wish we'd learned more math.

Yes, you have no understanding of complex numbers just because you can say j root (2).

If you really want to "be right", learn some more math, instead of parroting things you've picked up on internet forums. Sure as hell, if you tried it on with me in a maths class, I would ask you for a detailed explanation of your analysis.

Steve

You cannot do it with "real" numbers. No "real" number times itself can ever be negative, only positive.

You need to use complex or imaginary number sets to take a - SqrRt .

however, keep in mind that even though they are imaginary they do exist. they are just as real as "real numbers"

Well, they are just a conceptual as "real" numbers... All numbers are a "construct."

the square root of any negative number is always going to be i. this is because there is no number which you can square to get a negative number, it will always be positive.

No. i is specifically square root of -1. Square root of -2 is the square root of 2 times the square root of -1. Burf has the right answer.

You need to invoke i.
-2 = -1 x 2
so (root) -2 = (root) (-1 x 2),
which is (root) 2i (i being (root) -1

L