Question

Let g(x) = x² + 4x -1 . Evaluate each of the following: a. g(-4)b. g(7)c. g(-1/2)

Answer 1

Given:

`g\mleft(x\mright)=x^(2)+4x-1`

Evaluate the function at given numbers.

a) at x = -4,

`\begin{gathered} g\mleft(x\mright)=x^2+4x-1 \\ g\mleft(-4\mright)=(-4)^2+4(-4)-1 \\ g(-4)=16-16-1 \\ g(-4)=-1 \end{gathered}`

Answer: g(-4)= -1

b) at x = 7,

`\begin{gathered} g(x)=x^2+4x-1 \\ g(7)=7^2+4(7)-1 \\ g(7)=49+28-1 \\ g(7)=76 \end{gathered}`

Answer: g(7) = 76

c) at x = -1/2

`\begin{gathered} g(x)=x^2+4x-1 \\ g(-(1)/(2))=(-(1)/(2))^2+4(-(1)/(2))-1 \\ g(-(1)/(2))=(1)/(4)-2-1 \\ g(-(1)/(2))=(1)/(4)-3 \\ g(-(1)/(2))=(1-12)/(4) \\ g(-(1)/(2))=-(11)/(4) \end{gathered}`

Answer: g(-1/2) = -11/4