This post is about derivatives of Polar Equations. Because of polar equation,  Polar equation like  parametric equations of the curve where the angle θ is parameter. As well as equations have parameter (r,θ).

For this polar equation, the parametric equations are x ( θ) = cos θ and y ( θ) = sin θ. Therefore, the derivative is which matches what we got for the parametric derivative of a circle.

derivatives-and-equations-in-polar-coordinates-worksheet-2

Derivative of Polar