Find , when
Theorem: y and x are given in a different variable that is θ . We can find by finding and and then dividing them to get the required thing. = = a× 3 sin2θ × cosθ (using the chain rule = 3sin2θ× = 2sin2θ × cosθ ) = 3asin2θcosθ . ………..(1) = a × (3cos2θ)× (-sinθ ) (using chain rule = 2cosθ× = 2 cosθ × (-sinθ ) ) = -3asinθcos2θ. Dividing (1) and (2), we get = = . = -tanθ