मराठी

Prove that: secθ-1secθ+1+secθ+1secθ-1=2cosecθ

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प्रश्न

Prove that: `sqrt((sec theta - 1)/(sec theta + 1)) + sqrt((sec theta + 1)/(sec theta - 1)) = 2 cosec theta`

बेरीज
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उत्तर

LHS = `sqrt((1/cos theta - 1)/(1/cos theta + 1)) + sqrt((1/cos theta +1)/(1/cos theta - 1))`

`= sqrt(((1 - cos theta)/cos theta)/((1+ cos theta)/cos theta)) + sqrt(((1 + cos theta)/cos theta)/((1 - cos theta)/cos theta)`

`= sqrt((1 - cos theta)/(1 + cos theta)) +sqrt((1 + cos theta)/(1 - cos theta))`

`= sqrt((1 - cos theta)/(1 + cos theta) xx (1 - cos theta)/(1 - cos theta)) + sqrt((1 + cos theta)/(1 - cos theta) xx (1 + cos theta)/(1 + cos theta))`

`= sqrt((1 - cos theta)^2/(1 - cos^2 theta)) + sqrt((1 + cos theta)^2/(1 - cos^2 theta))`

`=(1 - cos theta)/sin theta + (1 + cos theta)/sin theta`

`= (1 - cos theta + 1 + cos theta)/sin theta`

`= 2/sin theta`

= 2 cosec

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पाठ 11: Trigonometric Identities - Exercise 11.1 [पृष्ठ ४७]

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आर.डी. शर्मा Mathematics [English] Class 10
पाठ 11 Trigonometric Identities
Exercise 11.1 | Q 83.1 | पृष्ठ ४७

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