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Prove the Following Identity : Cos E C a Cos E C a − 1 + Cos E C a Cos E C a + 1 = 2 Sec 2 a - Mathematics

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Question

Prove the following identity : 

`(cosecA)/(cosecA - 1) + (cosecA)/(cosecA + 1) = 2sec^2A`

Sum

Solution

`(cosecA)/(cosecA - 1) + (cosecA)/(cosecA + 1) = 2sec^2A`

LHS = `(cosecA)/(cosecA - 1) + (cosecA)/(cosecA + 1)`

= `(cosec^2A + cosecA + cosec^2A - cosecA)/(cosec^2A - 1)`

= `(2cosec^2A)/cot^2A(Q cosec^2A - 1 = cot^2A)`

= `(2/sin^2A)/(cos^2A/sin^2A) = 2/cos^2A = 2sec^2A`

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Chapter 21: Trigonometric Identities - Exercise 21.1

APPEARS IN

Frank Mathematics - Part 2 [English] Class 10 ICSE
Chapter 21 Trigonometric Identities
Exercise 21.1 | Q 3.08
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