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Question
`tanA/(1 + tan^2A)^2 + cotA/(1 + cot^2A)^2` = sin A cos A
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Solution
डावी बाजू = `tanA/(1 + tan^2A)^2 + cotA/(1 + cot^2A)^2`
= `tanA/(sec^2A)^2 + cotA/(cosec^2A)^2` .........`[(∵ 1 + tan^2θ = sec^2θ), (∴ 1 + cot^2θ = cosec^2θ)]`
= `tanA/sec^4A + cotA/(cosec^4A)`
= `tanA xx 1/sec^4A + cotA xx 1/(cosec^4A)`
= `sinA/cosA xx cos^4A + cosA/sinA xx sin^4A`
= sin A cos3A + cos A sin3A
= sin A cos A(cos2A + sin2A)
= sin A cos A (1) ........[∵ sin2θ + cos2θ = 1]
= sin A cos A
= उजवी बाजू
∴ `tanA/(1 + tan^2A)^2 + cotA/(1 + cot^2A)^2` = sin A cos A
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`tanθ/(secθ - 1) = (tanθ + secθ + 1)/(tanθ + secθ - 1)`
sinθ × cosecθ = किती?
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खालील प्रश्नासाठी उत्तराचा योग्य पर्याय निवडा.
sin2θ + sin2(90 – θ) = ?
cosec θ.`sqrt(1 - cos^2theta) = 1` हे सिद्ध करा.
`sec"A"/(tan "A" + cot "A")` = sin A हे सिद्ध करा.
sec2θ – cos2θ = tan2θ + sin2θ हे सिद्ध करा.
`(1 + sec "A")/"sec A" = (sin^2"A")/(1 - cos"A")` हे सिद्ध करा.
जर cos A + cos2A = 1, तर sin2A + sin4A = ?
θ चे निरसन करा:
जर x = r cosθ आणि y = r sinθ
