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प्रश्न
Prove the following identities:
`1 - sin^2A/(1 + cosA) = cosA`
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उत्तर
`1-sin^2A/(1 + cosA)`
= `(1 + cosA - sin^2A)/(1 + cosA)`
= `(cosA + cos^2A)/(1 + cosA)`
= `(cosA(1 + cosA))/(1 + cosA)`
= cos A
संबंधित प्रश्न
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Show that, cotθ + tanθ = cosecθ × secθ
Solution :
L.H.S. = cotθ + tanθ
= `cosθ/sinθ + sinθ/cosθ`
= `(square + square)/(sinθ xx cosθ)`
= `1/(sinθ xx cosθ)` ............... `square`
= `1/sinθ xx 1/square`
= cosecθ × secθ
L.H.S. = R.H.S
∴ cotθ + tanθ = cosecθ × secθ
