f(x) = x+ 1
g [f(x)] = x
g(x) = ?
To find the expression for g(x), we need to substitute f(x) into the equation g[f(x)] = x and solve for g(x).
Given f(x) = x + 1, we substitute it into g[f(x)] = x:
g[f(x)] = x
Replace f(x) with x + 1:
g[x + 1] = x
To solve for g(x), we isolate g(x) on one side of the equation:
g[x + 1] = x
Replace x + 1 with y:
g(y) = y - 1
Therefore, the expression for g(x) is g(x) = x - 1.