Given that, x=a\left(\cos \theta+\log \tan \left(\frac{\theta}{2}\right)\right) \text { and }
y=asin\theta
Ondifferentiatingw.r.t.\theta
respectively,wegetdθdx=a(−sinθ+tan(2θ)1⋅sec22θ⋅21)=a(−sinθ+sinθ1)=sinθacos2θand\frac{d y}{d \theta}=a \cos
θ∴dxdy=dx/dθdy/dθ=acos2θ/sinθacosθ=tanθ$