Question

Evaluate the function f(x)=x²-3x - 8 at the given values of the independent variable and simplify. a. f(8) b. f(x+9) c. f(-x) a. f(8) = (Simplify your answer.) b. f(x + 9) = (Simplify your answer.) c. f(-x) = (Simplify your answer.)

Answer 1

Explanation:

Given:
`f(x)=x^(2) -3x - 8`

To find:

a) f(8)

To find f(8), replace x with 8 in f(x)

`f(8) = 8^(2) -3(8) -8 = 32`

b) f(x+9)

To find f(x+9), replace x with x +9 in f(x)

`f(x+9) = (x +9)^(2) -3(x +9) -8 = x^(2) +18x+81-3x-27-8=x^(2) +15x+46`

c) f(-x)

To find f(-x), replace x with -x in f(x)

`f(x)=(-x)^(2) -3(-x) - 8 =x^(2) +3x-8`

This is how we simplify these expressions.