Objective Mathematics Set - III

1. If aN = {ax : x Î N} and bN Ç cN = dN, where b, c Î N are relatively prime, then
A. c = bd    B. b = cd    C. d = bc    D. none of the above

2. A square root of 3 + 4i is
A. Ö3 + i    B. 2 - i    C. 2 + i    D. none of the above

3. If the roots of x2 - bx + c = 0 are consecutive integers, then b2 - 4c is equal to
A. 4    B. 3    C. 2    D. 1

4. Condition that the two lines represented by the equation ax2 + 2hxy + by2 = 0 to the perpendicular is
A. a = - b    B. ab = 1    C. a = b    D. ab = -1

5. If A Í B, then A Ç B is equal to
A. Bc    B. Ac    C. B    D. A