7 cos (x)
d / 7 \ --\cos (x)/ dx
Let u=cos(x)u = \cos{\left(x \right)}u=cos(x).
Apply the power rule: u7u^{7}u7 goes to 7u67 u^{6}7u6
Then, apply the chain rule. Multiply by ddxcos(x)\frac{d}{d x} \cos{\left(x \right)}dxdcos(x):
The derivative of cosine is negative sine:
The result of the chain rule is:
The answer is:
6 -7*cos (x)*sin(x)
5 / 2 2 \ 7*cos (x)*\- cos (x) + 6*sin (x)/
4 / 2 2 \ 7*cos (x)*\- 30*sin (x) + 19*cos (x)/*sin(x)