Solve Function Composition
1. State the problem: We are given two functions $f(x) = x^2 + 1$ and $g(x) = x - 5$. We need to solve the equation $f(g(x)) = g(f(x))$.
2. Find $f(g(x))$: Substitute $g(x)$ into $f$.
$$f(g(x)) = f(x - 5) = (x - 5)^2 + 1$$
Expand the square:
$$= (x^2 - 10x + 25) + 1 = x^2 - 10x + 26$$
3. Find $g(f(x))$: Substitute $f(x)$ into $g$.
$$g(f(x)) = g(x^2 + 1) = (x^2 + 1) - 5 = x^2 - 4$$
4. Set the two expressions equal and solve for $x$:
$$x^2 - 10x + 26 = x^2 - 4$$
Subtract $x^2$ from both sides:
$$-10x + 26 = -4$$
Add $10x$ to both sides:
$$26 = 10x - 4$$
Add 4 to both sides:
$$30 = 10x$$
Divide both sides by 10:
$$x = 3$$
5. Final answer:
$$x = 3$$