To differentiate f(x)=[sinx+tanxsinxcosx]3,
we use chain rule and quotient rule.
Let f(x)=(g(x))3, where g(x)=sinx+tanxsinxcosx
Now as f(x)=(g(x))3, dfdg=3(g(x))2
and usiing quotient rule dgdx=sinxcosx×(cosx+sec2x)−(sinx+tanx)(cos2x−sin2x)sin2xcos2x
= sinxcos2x+sinxsecx−sinxcos2x−tanxcos2x+sin3x+sin2xtanxsin2xcos2x
= sinxcos2x+tanx−sinxcos2x−sinxcosx+sin3x+sin2xtanxsin2xcos2x
= 1sinx+1sinxcos3x−1sinx−1sinxcosx+sinxcos2x+sinxcos3x
= 1sinxcos3x−1sinxcosx+sinxcos2x+sinxcos3x
= 1−cos2xsinxcos3x+sinx(cosx+1)cos3x
= sinxcos3x+sinx(cosx+1)cos3x
= sinx(cosx+2)cos3x
and dfdx=dfdg×dgdx
= 3(sinx+tanxsinxcosx)2sinx(cosx+2)cos3x