Differentiate, y=sin4xcos7x

Differentiate, y=sin4xcos7x

y=sin4x cos7x=122sin4xcos7x 

y=12(sin11xsin3x) 

differentiating with respect  to x 

dydx=12[ddx(sin11xsin3x)] 

=12[cos11xddx(11x)cos3xddx(3x)] 

=12[11cos11x3cos3x]