What is the derivative of $y=(cosx)(tanx)$ ?

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Answer 1 · 2015-04-01T19:32:53

It is $cosx$

You could use the product rule and simplify later, but I think it's easier to simplify first: $tanx = sinx/cosx$ , so this $y$ simplifies to :

$y=cosx tanx = cosx sinx/cosx=sinx$

So $y' = cosx$

What is the derivative of y=(cosx)(tanx)y=(cosx)(tanx)?