मराठी

Prove the following trigonometric identities. (1 - sin θ)/(1 + sin θ) = (sec θ - tan θ)^2

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प्रश्न

Prove the following trigonometric identities.

`(1 - sin θ)/(1 + sin θ) = (sec θ - tan θ)^2`

Prove that:

`(1 - sin θ)/(1 + sin θ) = (sec θ - tan θ)^2`

सिद्धांत
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उत्तर

We have to prove  `(1 - sin θ)/(1 + sin θ) = (sec θ - tan θ)^2`

We know that, sin2 θ + cos2 θ = 1

Multiplying both numerator and denominator by  (1 − sin θ), we have

`(1 - sin θ)/(1 + sin θ) = ((1 - sin θ)(1 -  sin θ))/((1 + sin θ)(1 - sin θ))`

`= (1 - sin θ)^2/(1 - sin^2 θ)`

`= ((1 - sin θ)/cos θ)^2`

`= (1/cos θ - sin θ/cos θ)^2`

`= (sec θ - tan θ)^2`

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पाठ 18: Trigonometric identities - CHAPTER TEST [पृष्ठ ४२७]

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नूतन Mathematics [English] Class 10 ICSE
पाठ 18 Trigonometric identities
CHAPTER TEST | Q 5. | पृष्ठ ४२७

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