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(cosθ - (-θ sinθ + cosθ )) {by using product rule, while differentiating θcosθ } = a(θsinθ ) ………..(1) = a(-sinθ +θ cosθ +sinθ ) {by using product rule, while differentiating θcosθ } = a× θcosθ ……….(2) Dividing (1) and (2), we get = = tanθ ANS