Answer :
Answer:
Any value of x
Step-by-step explanation:
Given
[tex]f(x) = \sqrt{x^2 - 1}[/tex]
[tex]g(x) = \sqrt{x^2 + 1}[/tex]
Required
What value of x is [tex]f(g(x)) = g(f(x))[/tex]
Solving for f(g(x))
[tex]f(x) = \sqrt{x^2 - 1}[/tex]
[tex]f(g(x)) = \sqrt{(\sqrt{x^2 + 1})^2 - 1}[/tex]
Solve the inner square
[tex]f(g(x)) = \sqrt{(x^2 + 1 - 1}[/tex]
[tex]f(g(x)) = \sqrt{x^2 } }[/tex]
[tex]f(g(x)) = x[/tex]
Solving g(f(x))
[tex]g(x) = \sqrt{x^2 + 1}[/tex]
[tex]g(f(x)) = \sqrt{(\sqrt{x^2 - 1})^2 + 1}[/tex]
[tex]g(f(x)) = \sqrt{x^2 - 1 + 1}[/tex]
[tex]g(f(x)) = \sqrt{x^2 }[/tex]
[tex]g(f(x)) = x[/tex]
Equate f(g(x)) and g(f(x))
[tex]f(g(x)) = g(f(x))[/tex]
[tex]x = x[/tex]
This implies that [tex]f(g(x)) = g(f(x))[/tex] at any value of x