6. Let A = {1, 2, 3, 4, 6}. Let R be the relation on A defined by {(a, b): a, b E A, b is exactly divisible by a}. (i) Write R in roster form (ii) Find the domain of R (iii) Find the range of R. 7. Prove the following by using the principle of mathematical induction for all n = N: 32n+28n9 is divisible by 8. www. 8. Prove that: (sin 3x + sin x) sin x + (cos 3x - cos x) cos x = 0. 3 9. If a, b, c are 3 consecutive integers, prove that (a-i) (a + i) (c+i) (ci) = b4 + 1. 4 3. 3 10. If f(x)=4x find f(x+1)-f(x) in terms off (x). 2