How do you find the derivative of $f(t) = cos((pit)/4)$ ?

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Answer 1 · 2015-04-11T21:05:20

Here you can use the Chain Rule to derive $cos$ first and then its argument to get:
$f'(t)=-sin(pit/4)*pi/4=-pi/4sin(pit/4)$

How do you find the derivative of f(t) = cos((pit)/4)f(t) = cos((pit)/4)?