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Examine the continuity of f, where f is defined by: f(x) = {sin⁡𝑥−cos⁡𝑥, if 𝑥≠0−1, if 𝑥=0 - Mathematics

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प्रश्न

Examine the continuity of f, where f is defined by:

f(x) = `{(sin x - cos x", if"  x != 0),(-1", if"  x = 0):}`

योग
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उत्तर

f(x) = `{(sin x - cos x", if"  x != 0),(-1", if"  x = 0):}`

Approach 1:

If f(x) is continuous at x = c, it implies:

f(c) = `lim_(x -> c^+)` f(x) = `lim_(x -> c^-)` f(x)

⇒ −1 = sin 0 − cos 0 = −sin 0 − cos 0

⇒ −1 = −1 = −1

This shows that f(x) is continuous at x = 0.

Approach 2:

c ≠ 0 and c ⊂ R

If f(x) is continuous at x = c, it implies:

sin c − cos c is continuous, i.e. sin c and cos c are continuous functions, which is true.

That is, f(x) is also continuous at x ≠ 0.

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  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 5: Continuity and Differentiability - Exercise 5.1 [पृष्ठ १६१]

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एनसीईआरटी Mathematics Part 1 and 2 [English] Class 12
अध्याय 5 Continuity and Differentiability
Exercise 5.1 | Q 25 | पृष्ठ १६१

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