Question

Derivative of f(x)=sin^2 ((pi x)/4).
Professor skimmed this and did not give good clarification in his example, nor are there good examples in the text.

Answer 1

Chain rule.
derivative of sin^2(x)=2sin(x)cos(x)*dx
so derivative of sin^2(pi*x/4)=2sin(pi*x/4)cos(pi*x/4)*(pi/4)

Answer 2

Did we lose a 2 in the simplified solution?

Answer 3

simplified \[\frac{ \pi }{ 2 }\sin(\frac{ \pi x }{ 4 })\cos(\frac{ \pi x}{4})\]

Answer 4

That looks more like what I was getting :)

Answer 5

Thanks so much for your help :)