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F(x) = ,if,if{|x-4|2(x-4),if x≠40,if x=4 at x = 4 - Mathematics

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Question

f(x) = `{{:(|x - 4|/(2(x - 4))",", "if"  x ≠ 4),(0",", "if"  x = 4):}` at x = 4

Sum
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Solution

We have, f(x) = `{{:(|x - 4|/(2(x - 4))",", "if"  x ≠ 4),(0",", "if"  x = 4):}`

At x = 4

L.H.L. = `lim_(x -> 4^-) |x - 4|/(2(x - 4))`

= `lim_("h" -> 0) (|(4 - "h") - 4|)/(2[(4 - "h") - 4])`

= `lim_("h" -> 0) |-"h"|/(-2"h")`

= `lim_("h" -> 0) |"h"|/(-2"h")`

= `lim_("h" -> 0) "h"/(-2"h")`

= `(-1)/2`

But given that f(4) = 0 ≠ L.H.L.

So, f(x) is discontinuous at x = 4.

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Chapter 5: Continuity And Differentiability - Exercise [Page 107]

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NCERT Exemplar Mathematics [English] Class 12
Chapter 5 Continuity And Differentiability
Exercise | Q 5 | Page 107

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