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Evaluate the following : Find the limit of the function, if it exists, at x = 1 f(x) = {7-4xforx<1x2+2forx≥1

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Question

Evaluate the following :

Find the limit of the function, if it exists, at x = 1

f(x) = `{(7 - 4x, "for", x < 1),(x^2 + 2, "for", x ≥ 1):}`

Sum
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Solution

f(x) = `{(7 - 4x, "for", x < 1),(x^2 + 2, "for", x ≥ 1):}`

`lim_(x -> 1^-)` f(x) = `lim_(x -> 1)` (7 − 4x)

= 7 – 4(1)

= 3

`lim_(x -> 1^+)` f(x) = `lim_(x -> 1)` (x2 + 2)

= (1)2 + 2

= 3

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

∴ `lim_(x -> 1^+)` f(x) exists and is equal to 3.

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Chapter 7: Limits - Miscellaneous Exercise 7.2 [Page 159]

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