Let f(x) = 0 ( x - x ( 2 ) (x - 1)1 + x ( 2 )(x - 1) ), x R. Consider the following two statements : (I) f(x) is discontinuous at x = 1. (II) f(x) is continuous at x = -1. Then,
- Neither (I) nor (II) is True
- Only (II) is True
- Only (I) is True
- Both (I) and (II) are True
Answer
(1) Neither (I) nor (II) is True
Solution
Let n = 1 , so x2/ = (x2)n.
For |x| < 1, (x2)n 0, so f(x) = x.
For |x| > 1, dividing by (x2)n gives f(x) = - (x - 1)x - 1.
For |x| = 1, (x2)n = 1, so f(x) = x - (x - 1)x.
At x = 1: f(1) = = -1
LHL = x 1- x = -1; RHL = x 1+ - (x - 1)x - 1 = -1
so f is continuous at x = 1, and (I) is false.
At x = -1: RHL = x -1+ x = -1
LHL = x -1- - (x - 1)x - 1 = - (-2)-2 = - 22 -1
so f is discontinuous at x = -1, and (II) is false.
Answer: (1)