# math questionHow to differentiate y = cos x*ln x?

### 1 Answer | Add Yours

We'll have to differentiate with respect to x, using the product rule:

(u*v)' = u'*v + u*v'

Let u = cos x and v = ln x

y' = (cos x)'*(ln x) + (cos x)*(ln x)'

y' = -sin x*ln x + (cos x)/x

The first derivative of the function is y' = -sin x*ln x + (cos x)/x