use chain rule to find the derivative of the function. f(x) = sin 2x a. f(x) = 2 sin 2x b. f(x) = 2 sin x c…

use chain rule to find the derivative of the function. f(x) = sin 2x a. f(x) = 2 sin 2x b. f(x) = 2 sin x c. f(x) = 2 cos 2x d. f(x) = 2 cos x reset selection
Answer
Explanation:
Step1: Let $u = 2x$
Let $y=\sin u$.
Step2: Find $\frac{du}{dx}$ and $\frac{dy}{du}$
$\frac{du}{dx}=2$, $\frac{dy}{du}=\cos u$.
Step3: Apply chain - rule
The chain - rule states that $\frac{dy}{dx}=\frac{dy}{du}\cdot\frac{du}{dx}$. Substitute $u = 2x$ back in. $\frac{dy}{dx}=\cos u\cdot2=2\cos 2x$.
Answer:
C. $f'(x)=2\cos 2x$