Step-by-step explanation:
step 1. f(1/(a + 1)) = 1/(1/(a + 1))^2 - 1
step 2. f(1/(a + 1)) = 1/(1/(a + 1)^2) - 1
step 3. f(1/(a + 1)) = (a + 1)^2 - 1
step 4. f(1/(a + 1)) = a^2 + 2a + 1 - 1
step 5. f(1/(a + 1)) = a^2 +2a
step 6. f(1/(a + 1)) = a(a + 2)
