What is the derivative of cos(x^2)?

1 Answer
Sep 4, 2016

- 2x sin(x^(2))

Explanation:

We have: cos(x^(2))

This expression can be differentiated using the "chain rule".

Let u = x^(2) => (d) / (dx) (u) = 2x and v = cos(u) => (d) / (du) (cos(u)) = - sin(u):

=> (d) / (dx) (cos(x^(2)) = 2x cdot - sin(u)

=> (d) / (dx) (cos(x^(2)) = - 2x sin(u)

We can now replace u with x^(2):

=> (d) / (dx) (cos(x^(2)) = - 2x sin(x^(2))