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Find the value of the constant k so that the function f defined below is continuous at x = 0, where f(x) = ,k,{1-cos4x8x2,x≠0k,x=0 - Mathematics

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प्रश्न

Find the value of the constant k so that the function f defined below is continuous at x = 0, where f(x) = `{{:((1 - cos4x)/(8x^2)",", x ≠ 0),("k"",", x = 0):}`

योग
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उत्तर

It is given that the function f is continuous at x = 0.

Therefore, `lim_(x -> 0) "f"(x)` = f(0)

⇒ `lim_(x -> 0) (1 - cos4x)/(8x^2)` = k

⇒ `lim_(x -> 0) (2sin^2 - 2x)/(8x^2)` = k

⇒ `lim_(x -> 0) ((sin 2x)/2x)^2` = k

⇒ k = 1

Thus, f is continuous at x = 0 if k = 1.

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अध्याय 5: Continuity And Differentiability - Solved Examples [पृष्ठ ९१]

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एनसीईआरटी एक्झांप्लर Mathematics [English] Class 12
अध्याय 5 Continuity And Differentiability
Solved Examples | Q 1 | पृष्ठ ९१

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