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Prove that 1+secAsec A=sin2A1-cosA - Geometry Mathematics 2

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प्रश्न

Prove that `(1 + sec "A")/"sec A" = (sin^2"A")/(1 - cos"A")`

योग
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उत्तर

L.H.S = `(1 + sec "A")/"sec A"`

= `1/"sec A" + "sec A"/"sec A"`

= cos A + 1

= `(1 + cos "A") xx (1 -  cos"A")/(1 - cos"A")`

= `(1 - cos^2"A")/(1 - cos"A")`

= `(sin^2"A")/(1 - cos"A")`     .......`[(because sin^2"A" + cos^2"A" = 1),(therefore 1 - cos^2"A" = sin^2"A")]`

= R.H.S

∴ `(1 + sec "A")/"sec A" = (sin^2"A")/(1 - cos"A")`

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अध्याय 6: Trigonometry - Q.3 (B)

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