Let f(x) = 22 - 2x.Evaluate f(-2) =Solve f(x) = -1.

Question

asked Jan 14, 2023 49.2k views

1 Answer

Lalji Dhameliya · Answer 1 · 2023-01-21T06:51:10+0000

Question:

Solution:

Consider the following function:

then:

$f(-2)=(-2)^2-2(-2)\text{ = 4 +4 = 8}$

thus,

$f(-2)=\text{ 8}$

now, if f(x)=-1 this is equivalent to say:

$f(x)=x^2-2x\text{ = -1}$

that is:

$x^2-2x\text{ = -1}$

this is equivalent to:

$x^2-2x\text{ +1}=0$

now, solving this equation using the quadratic equation:

where a = 1, b = -2 and c= 1, we get:

$x\text{ = }1$

so that, we can conclude that the correct answers are:

$f(-2)=\text{ 8}$

and

$x\text{ = }1$