Sets, Functions & Relations Part - 3

11) Let R is the set of real numbers,

      such that the function f : R→R and g:

     R→R are defined by f(x) = x^2+3x+1 

     and g(x) = 2x - 3. Find (fog)

    (a) 4x^2+6x+1

    (b) x^2+6x+1

    (c) 4x^2 -6x+1.

12) If f: R→R, f(x) = 2x +7, then the

      inverse of f is:

      (a) f^-1(x) = (x - 7)/2

      (b) f^-1(x) = (x + 7)/2

      (c) f^1(x) = (x - 3)/2

      (d) None

13) If A = {x: x^2 - 3x + 2 = 0},

      B = {x: x^2 + 4x - 12 =0}, then

       B - A is equal to :

     (a) {-6}

     (b) {1}

     (c) {1,2}

     (d) {2,-6}