Respuesta :
Answer:
Option 3 - f(x)= 4x, [tex]g(x) = \frac{1}{4}x[/tex]
Step-by-step explanation:
To find : Which two functions are inverses of each other?
Solution :
Two functions are inverse if [tex]f(g(x))=x=g(f(x))[/tex]
Now, we find one by one
1) f(x)= x, g(x) = -x
[tex]f(g(x))=f(-x)=-x\neq x[/tex]
Not true.
2) f(x)= 2x, [tex]g(x) = -\frac{1}{2}x[/tex]
[tex]f(g(x))=f(-\frac{1}{2}x)=2\times(-\frac{1}{2}x)=-x\neq x[/tex]
Not true.
3) f(x)= 4x, [tex]g(x) = \frac{1}{4}x[/tex]
[tex]f(g(x))=f(\frac{1}{4}x)=4\times(\frac{1}{4}x)=x[/tex]
[tex]g(f(x))=f(4x)=\frac{1}{4}\times 4x=x[/tex]
i.e. [tex]f(g(x))=x=g(f(x))[/tex] is true.
So, These two functions are inverse of each other.
4) f(x)= -8x, [tex]g(x) =8x[/tex]
[tex]f(g(x))=f(8x)=8\times(-8x)=-64x\neq x[/tex]
Not true.
Therefore, Option 3 is correct.