GraphingCalculator 3.5;
Window 42 70 680 704;
PaneDivider 207;
Slider 0.1 1.57;
SliderSteps 20;
SliderControlValue 18;
SliderVariable a;
Theta -50 12;
Parameter a = 2;
Expr r=e^(theta*cot([a]));
Text "This is the polar equation for equiangular spiral. It is defined as a spiral such that all radii (lines passing origin) cuts the curve in a constant angle a.
We can see that as a goes from 0 to Pi/2, the curve has larger curvature, from a near straight line to circle. XahLee.org, 2004.";