If f : [ 0 , 2 ) → ℝ is defined by f x = 1 + 2 x k  for  0 ≤ x < 1 k x &#160…

If f:[0,2) is defined by fx=1+2xk for 0x<1kx for 1x<2, where k>0 and f is such that limx1-fx=limx1+fx, then the value of k2 is
  1. 2
  2. 1
  3. 4
  4. 14

Solution

Given:

fx=1+2xk for 0x<1kx for 1x<2

Now,

limx1-fx=limx1+fx

1+2k=k

k+2=k2

k2-k-2=0

k2-2k+k-2=0

k+1k-2=0

k=2 and -1

But, k>0

Hence, k=2k2=4.

 

Asked in: AP EAMCET 2018 (25 Apr Shift 1)

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