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प्रश्न
दाखवा की: `tanA/(1 + tan^2 A)^2 + cotA/(1 + cot^2A)^2` = sinA × cosA.
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उत्तर
डावी बाजू = `tanA/(1 + tan^2 A)^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`
= sinA cos3A + cosA sin3A
= sinA cosA (cos2A + sin2A)
= sinA cosA (1) ...[∵ sin2θ + cos2θ = 1]
= sinA cosA
= उजवी बाजू
∴ `tanA/(1 + tan^2A)^2 + cotA/(1 + cot^2A)^2` = sinA cosA
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संबंधित प्रश्न
`tanθ/(secθ + 1) = (secθ - 1)/tanθ`
`(tan^3θ - 1)/(tanθ - 1)` = sec2θ + tanθ
खालील प्रश्नासाठी उत्तराचा योग्य पर्याय निवडा.
`(1 + cot^2"A")/(1 + tan^2"A")` = ?
`(sin^2theta)/(cos theta) + cos theta` = sec θ हे सिद्ध करा.
cot θ + tan θ = cosec θ × sec θ, हे सिद्ध करण्यासाठी खालील कृती पूर्ण करा.
कृती:
डावी बाजू = `square`
= `square/sintheta + sintheta/costheta`
= `(cos^2theta + sin^2theta)/square`
= `1/(sintheta*costheta)` ......`[cos^2theta + sin^2theta = square]`
= `1/sintheta xx 1/square`
= `square`
= उजवी बाजू
`(1 + sintheta)/(1 - sin theta)` = (sec θ + tan θ)2 हे सिद्ध करा.
`sqrt((1 + cos "A")/(1 - cos"A"))` = cosec A + cot A हे सिद्ध करा.
`"cot A"/(1 - tan "A") + "tan A"/(1 - cot"A")` = 1 + tan A + cot A = sec A . cosec A + 1 हे सिद्ध करा.
(sin A + cos A) (cosec A – sec A) = cosec A . sec A – 2 tan A हे सिद्ध करा.
सिद्ध करा:
cotθ + tanθ = cosecθ × secθ
उकल:
डावी बाजू = cotθ + tanθ
= `cosθ/sinθ + sinθ/cosθ`
= `(square + square)/(sinθ xx cosθ)`
= `1/(sinθ xx cosθ)` ............... `square`
= `1/sinθ xx 1/square`
= cosecθ × secθ
= उजवी बाजू
∴ cotθ + tanθ = cosecθ × secθ
