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Find all points of discontinuity of f, where f is defined by f(x)={x10-1ifx≤1x2ifx>1 - Mathematics

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Question

Find all points of discontinuity of f, where f is defined by `f (x) = {(x^10 - 1, if x<=1),(x^2, if x > 1):}`

Sum

Solution

`f (x) = {(x^10 - 1, if x<=1),(x^2, if x > 1):}`

For x < 1, f(x) = x10 - 1 and

x > 1, f(x) = x2 is a polynomial function.

So this is a function.

At x = 1,

`lim_(x -> 1^-) f(x) = lim_(x -> 1^-)` (x10 - 1)

= `lim_(h -> 0)` [(1 - h)10 - 1]

= (1 - 0)10 - 1 = 1 - 1 = 0

`lim_(x -> 1^+) f(x) = lim_(x -> 1^+)` (x2)

= `lim_(h -> 0)` (1 + h)2

= `lim_(h -> 0)` (1 + h2 + 2h) = 1

Hence, f is not continuous at x = 1.

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Chapter 5: Continuity and Differentiability - Exercise 5.1 [Page 159]

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NCERT Mathematics [English] Class 12
Chapter 5 Continuity and Differentiability
Exercise 5.1 | Q 12 | Page 159

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