How do you differentiate $f (x) = x cos (\frac{π x}{2})$ $f(x) = xcos((pix)/2)$ using the chain rule?

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Answer 1 · 2016-02-24T01:04:45

This problem actually requires BOTH the chain rule and the product rule ...

$f'(x)=cos((pix)/2)+x(-sin((pix)/2)xxpi/2)$

Now simplify, ...

$cos((pix)/2)-(pix)/2sin((pix)/2)$

Hope that helped

How do you differentiate f(x) = xcos((pix)/2)f(x)=xcos(πx2)f(x) = xcos((pix)/2) using the chain rule?