If all the roots of `z^3+az^2+bz+c=0` are of unit modulus, then (A) `|a|le3` (B) `|b|le3` (C) `|c|=1` (D) none of these

The number of real roots xcosx=1 in [0,2pi] (A) 1 (B) 2 (C) 3 (D) none of these

The number of real roots xcosx=1 in [0,2pi] (A) 1 (B) 2 (C) 3 (D) none of these

The value of (z + 3) (barz + 3) is equivlent to (A) |z+3|^(2) (B) |z-3| (C) z^2+3 (D) none of these

If a : b=3:4, then 4a :3b= (a) 4:3 (b) 3:4 (c) 1:1 (d) None of these

If -2ltxlt3 , then; (a) 4ltx^2lt9 (b) 0le|x|2lt5 (c) 0lex^2lt9 (d) None of these

For a complex number Z, if all the roots of the equation Z^3 + aZ^2 + bZ + c = 0 are unit modulus, then

If for the matrix A ,\ A^3=I , then A^(-1)= (a) A^2 (b) A^3 (c) A (d) none of these

((-3)/2)^(-1) is equal to (a) 2/3 (b) 2/3 (c) 3/2 (d) none of these

The set of all values of a for which both roots of equation x^2-2ax+a^2-1=0 lies between -2 and 4 is (A) (-1,2) (B) (1,3) (C) (-1,3) (D) none of these

If for a square matrix A,A^2=A then |A| is equal to (A) -3 or 3 (B) -2 or 2 (C) 0 or 1 (D) none of these