When y=sin(pi*x), why does y'=cos(pi*x)*pi, not y'=cos(pi*x)?
It's the chain rule. when the argument of a trig function is a FUNCTION of x, you have take the derivative of the agrgument. So, in general
So than in this case y=f(u)=sinu and u=g(x)=pi*x, correct?
That is correct.
Thanks guys, I appreciate it.
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