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Show that the function defined by f(x) = cos (x2) is a continuous function.

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प्रश्न

Show that the function defined by f(x) = cos (x2) is a continuous function.

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उत्तर

Let f(x) = cos (x2)

Domain of f = R

Let a be any arbitrary real number.

`lim_(x->a^-)` f(x) = `lim_(h->0)` cos (a − h)2 = cos a2

`lim_(x->a^+)` f(x) = `lim_(h->0)` cos (a + h)2 = cos a2

Also f(a) = cos a2

Thus, `lim_(x->a^-)` f(x) = `lim_(x->a^+)` f(x) = f(a) ∀ a ∈ R

∴ f(x) = cos (x2) is continuous at a ∀ a ∈ R.

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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 31 | पृष्ठ १६१

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