Answer:
d. -22
Step-by-step explanation:
If F(x) is given by:
[tex]f(x)=(x^{3}+bx+6) g(x)[/tex]
The derivative is given by:
[tex]f'(x)=(3x^{2}+b) g(x)+(x^{3}+bx+6) g'(x)[/tex]
if f'(2)=0
[tex]f'(2)=(3(2)^{2}+b) g(2)+((2)^{3}+2b+6) g'(2)=0[/tex]
[tex]3(12+b)-(14+2b)=0[/tex]
[tex]36+3b-14-2b=0[/tex]
[tex]b=-22[/tex]