Question:
Solution:
Consider the following function:
[tex]f(x)=x^2-2x[/tex]
then:
[tex]f(-2)=(-2)^2-2(-2)\text{ = 4 +4 = 8}[/tex]
thus,
[tex]f(-2)=\text{ 8}[/tex]
now, if f(x)=-1 this is equivalent to say:
[tex]f(x)=x^2-2x\text{ = -1}[/tex]
that is:
[tex]x^2-2x\text{ = -1}[/tex]
this is equivalent to:
[tex]x^2-2x\text{ +1}=0[/tex]
now, solving this equation using the quadratic equation:
where a = 1, b = -2 and c= 1, we get:
[tex]x\text{ = }1[/tex]
so that, we can conclude that the correct answers are:
[tex]f(-2)=\text{ 8}[/tex]
and
[tex]x\text{ = }1[/tex]
