Question

find the slope of the tangent line to f(x)=4x^2 + 2x at x = 1. a 8 b none of these c 9 d 7 e 10

Explanation:

Step1: Find the derivative of f(x)

The derivative of $f(x)=4x^{2}+2x$ using the power - rule $\frac{d}{dx}(ax^{n})=nax^{n - 1}$ is $f^\prime(x)=\frac{d}{dx}(4x^{2})+\frac{d}{dx}(2x)=8x + 2$.

Step2: Evaluate the derivative at x = 1

Substitute $x = 1$ into $f^\prime(x)$. So $f^\prime(1)=8\times1+2=10$.

Answer:

E. 10