यदि ` x = a cos theta ` और , ` y = b sin theta , ` तो `(dy//dx)` ज्ञात कीजिए ।

Explanation

यहाँ `(dx)/(dtheta)= - a sin theta ` और ` (dy)/(dtheta) = b cos theta `
`:. (dy)/(dx) = (dy)/(d theta) /(dx)/(d theta) = (b cos theta )/(-a sin theta) = - b/a cot theta.`