a. for the function and point below, find f(a). b. determine an equation of the line tangent to the graph of…

a. for the function and point below, find f(a). b. determine an equation of the line tangent to the graph of f at (a,f(a)) for the given value of a. f(x)= - 2x³, a = - 2 a. f(a)=□
Answer
Explanation:
Step1: Find the derivative of f(x)
Using the power - rule $(x^n)'=nx^{n - 1}$, if $f(x)=-2x^{3}$, then $f'(x)=-2\times3x^{2}=-6x^{2}$.
Step2: Evaluate f'(a)
Given $a = - 2$, substitute $x=-2$ into $f'(x)$. So $f'(-2)=-6\times(-2)^{2}=-6\times4=-24$.
Step3: Find f(a)
Substitute $x = - 2$ into $f(x)$. $f(-2)=-2\times(-2)^{3}=-2\times(-8)=16$.
Step4: Use the point - slope form for the tangent line
The point - slope form of a line is $y - y_{1}=m(x - x_{1})$, where $(x_{1},y_{1})=(a,f(a))=(-2,16)$ and $m = f'(a)=-24$. So $y - 16=-24(x + 2)$. Expand to get $y-16=-24x-48$, then $y=-24x - 32$.
Answer:
a. $f'(a)=-24$ b. $y=-24x - 32$