Question

question 3
find the derivative of the function.
f(x) = 7cosx - 4x - 1

• 7 sin x - 4

no correct answer choice is given.

• 7 cos x - 4

7 cos x - 4
7 sin x - 4

Explanation:

Step1: Apply derivative rules

The derivative of $\cos x$ is $-\sin x$, and the derivative of $ax$ (where $a$ is a constant) is $a$, and the derivative of a constant is 0.

Step2: Differentiate each term

For $7\cos x$, its derivative is $7\times(-\sin x)= - 7\sin x$. For $-4x$, its derivative is $-4$. For $-1$ (a constant), its derivative is 0.

Step3: Combine the derivatives

$f'(x)=-7\sin x - 4+0=-7\sin x - 4$

Answer:

$- 7\sin x - 4$