Hello!

Please if I have y=f(sinx)

then

y'(x) should be f'(sinx)cosx

y''(x)= f''(sinx) cos x+f'(sinx)(-sinx)

y'''(x)= f'''(x)-2f''(sinx)sinx-f'(sinx)cos x

Is that correct?

The problem is I shoudl get

y'''(x)=f'''(sinx)cos^3x-3cosxsinxf''(sinx)-f'(sinx)cosx

where did I make the mistake?

Many thanks!!!