यदि `y=sin x cos 2x`, तब का मान ज्ञात कीजिएः की `(dy)/(dx)=y[cot x-2 tan 2x]`

Answer

1+log x

Explanation

`y=sin x cos 2x`
`Rightarrow (dy)/(dx)=sin x(d)/(dx)(cos 2x)+cos 2x (d)/(dx)(sin x)`
`=sin x (-2sin 2x)+cos 2x(cos x)`
`=y[(-2 sin x sin 2x+cos 2x cos x )/(y)]`
`=y[(-2 sin x sin 2x+cos 2x cos x )/(y)]`
`=y[(-2tan2x)+cot x]`
`=y(cot x-2tan2x)`