`(dy)/(dx)` ज्ञात कीजिए|
`x=a(cos theta+theta sin theta),y=a(sin theta-theta cos theta)`

Explanation

`x-a(cos theta+ theta sin theta)`
`rArr" "(dx)/(d theta)=a(-sin theta+ theta cos theta+sin theta)=a theta cos theta`
तथा `y=a(sin theta-theta cos theta)`
`rArr" "(dy)/(d theta)=a[cos theta-(- theta sin theta+cos theta)]=a theta sin theta`
अब `(dy)/(dx)=(dy//d theta)/(dx//d theta)=(a theta sin theta)/(a theta cos theta)=tan theta`