3. (4 pts) Prove that 9n2 + 12n + 8 = O(n), using the definition of the o notation. (You need to specify two positive constants, then prove that they satisfy the 0 definition.) 4. (4 pts) Prove that 9n2-10n + 3 = 2(na), using the definition of the 2 notation. (You need to specify two positive constants, then prove that they satisfy the 2 definition.)