# Parabola Plotting Web Pages

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## Introduction: Parabola Plotting Web Pages

Graphics have become more available on web pages. A web page that can design parabolas can show what is now available.

## Step 1:

Different applications require parabolas having different focal points. A parabola follows the following equation.

Y = X^2/(4*focal)

The old camera flash bulbs appeared to use a short focal length when compared to its radius. When the focal is 0.25, then Y will be unity when X is unity.

The web page to do this is only a text file. Feel free to save it as source on you computer.

## Step 2:

Solar application may need a long focal length. If the focal is 1, then Y will be 0.25 when X is one. The radius of the parabola can be thought of as being X. The depth of the parabola can be thought of as being Y.

## Step 3:

Some applications may require the focal point to be close to one half the depth. Using a focal which is at sqrt(1/8) will do the job.

## Step 4:

The new graphing feature can be extended such that a web page can print out the segments of a parabola. The web page that does this is only a text file. Select a focal and whether to plot segments or the sides. Feel free to save  this page on your computer. Look at the page's text.

## Step 5:

The parabola is design to step X from 0 to 1 in 0.1 units. The side view plots both the X steps and the corresponding Y steps as lines. This web page should be printable on a single sheet of page. Or it can be saved as a pdf file to be printed later.

## Step 6:

Half of a parabola can be constructed by printing out  six segments and a left and right side.

## Step 7:

The lines on the half parabola show how well all the X and Y dimension line up.

The plots are 700x700 bitmaps which avoid the auto scaling features found in most plotting resources. The plot will define a segment shape from a input  a focal length which is relative to the parabola's radius. By importing these plots into a graphic application for scaling, it should be possible to construct any type of parabola desired.