How do you find the derivative of $y = 2x cos(x)$ ?

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Answer 1 · 2016-01-17T04:16:31

$y'=2(cos(x)-xsin(x))$

$d/dx[f(x)g(x)]=f'(x)g(x)+f(x)g'(x)$

Thus,

$y'=cos(x)d/dx[2x]+2xd/dx[cos(x)]$

$y'=2cos(x)+2x(-sinx)$

$y'=2(cos(x)-xsin(x))$

How do you find the derivative of y = 2x cos(x)y = 2x cos(x)?