Circles and Ellipses

Subject Areas

Tools / Misc

bCalc

drag-N-drop

scrnGC2: Calc Input

scrnGC3: f(x) Plot Input

scrnGC4: g(x) Plot Input

The inputs above will be hidden when the program finally gets launched. Currently, I am not hiding them even when you close the calculator. The purpose of the inputs is to help in debugging. This allows you to enter simple code on the calculator screen but the program translates the input to javascript math. Give it a try and see if you notice any obvious problems or have suggestions for improvements.

gCalc

drag-N-drop

Select precision* of answer:

Select angle mode:

Enter expression to evaluate here:

The answer is shown below:

Enter function to be plotted:

f(x) =

Enter 2nd function, if needed:

g(x) =

Change or reset the x-y scaling below:

x_min =

x_max =

y_min =

y_max =

Accuracy Disclaimer

The javascript math object methods used for this calculator are not accurate for very large or very small numbers. In particular, the trigonometric functions may yield very small answers that should actually be zero or very large answers that should be infinite. This typically occurs at 90° or pi/2 intervals.

DO NOT USE WHERE HIGH PRECISION IS REQUIRED. USE AT YOUR OWN RISK.

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Circles and Ellipses

General Form:

Standard Form:

Center

Vertices

Foci

h =

k =

a =

b =

The center of the ellipse is at (h,k). The width of the blue box is determined by a and
the height is determined by b. The edges of the blue box, which is what constrains the
ellipse, are at (h ± a, k ± b). Try different values of h, k, a and b to see their effect.
When a = b, you have a circle. The General Form was derived by multiplying the Standard Form by a²b². It may not be fully reduced.