3. a) f(g) inlocuiesti x-ul din f(x) cu cel din g(x)
f(g(1)) = f(1⁶) = f(1) = 1³ = 3
g(f(2)) = g(2³) = g(8) = 8⁶
3+8⁶ = 3 + .... =
b) f(g(∛2)) = f(∛2)⁶ = f(2²) = 4² = 16
g(f(-∛3) = g(-∛3)³ = g(-3) = (-3)⁶ = 3⁶
16 - 3⁶ = ....
7. f(1) = V1 =1
f(1/9) = V(1/9) = V1/V9 = 1/3
f(1/25) = V(1/25) = 1/5
1+9*1/3 - 10*1/5= 1+3-2 = 5-2 = 3
8. f(8) = ∛8 = ∛2³ = 2
f(1/64) = ∛(1/64) = ∛(1/4)³ = 1/4
f(-1/8) = ∛(-1/8) = ∛(-1/2)³ = -1/2
2*1/4 + (-1/2) = 1/2-1/2 = 0