Question

Using the function f(x)=-x^2+8x-13 find f(4)

Answer 1

3

Explanation:

You plug in 4.

f(4)= -(4)^2+8(4)-13

f(4)= -16+32-13

f(4)= 16-13

f(4)=3

Answer 2

f(4) = 3

Explanation:

f(x) = -
`x^(2)` + 8x - 13

To find f(4), substitute 4 for all instances of x:

f(4) = -(4
`)^(2)` + 8(4) - 13

Simplify the exponent:

f(4) = -16 + 8(4) - 13

Multiply:

f(4) = -16 + 32 - 13

Combine terms:

f(4) = 3