How do I calculate second derivative of involute of circle? I found its first derivative is tantheta but I have no clue how to proceed further

Question

Parametric equations of this involute curve are given as = (sin − cos ) and = (cos + sin ).

Answer 1

$$ \frac{dy}{dx}= \frac{\frac{dy}{d\theta}}{\frac{dx}{d\theta}}=\tan\theta $$

This is how you proceed further:

$$ \frac{d^2y}{dx^2}=\frac{\frac{d}{d\theta}\left(\frac{dy}{dx}\right)}{\frac{dx}{d\theta}}$$