Relations And Functions

  • Question
    CBSEENMA11013308

    Are the following pair of sets equal? Give reasons :

    (i) A = {2, 3}, B = {x : x is solution of x2 + 5x + 6 = 0}

    (ii) A = {x : x is a letter in the word FOLLOW}, B = {y : y is a letter of word WOLF}

     

    Solution

    (i)                   A    =  {2, 3}
                          B   =  { x :  is solution of x2 + 5x + 6 = 0}
     
    Now,               x2 + 5x + 6 = 0                   rightwards double arrow      (x+2)(x+3) = 0
     
    rightwards double arrow                 x = -2, x = -3            rightwards double arrow     B = {-2, -3}
    Clearly,  space space space space space space space space space space space straight A space not equal to space straight B 

    (ii)           A = { x: x is a letter in the word FOLLOW
     
    rightwards double arrow          A = { F, O, L, W}
    Also,       B = { y : y  is a letter of the word WOLF}
    rightwards double arrow          B  = { W, O, L, F}
    Hence,     A = B.

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