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महाराष्ट्र राज्य शिक्षण मंडळएस.एस.सी (इंग्रजी माध्यम) इयत्ता १० वी

Prove that: sec4⁡A(1−sin4⁡A)−2tan2⁡A=1 - Geometry Mathematics 2

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प्रश्न

Prove that:

\[\sec^4 A\left( 1 - \sin^4 A \right) - 2 \tan^2 A = 1\]
बेरीज

उत्तर

L.H.S = \[\sec^4 A\left( 1 - \sin^4 A \right) - 2 \tan^2 A\]

\[ = \sec^4 A - \sec^4 A \sin^4 A - 2 \tan^2 A\]

= `(sec^2"A")^2 - 1/(cos^4"A"). sin^4"A" - 2tan^2"A"   ...[secθ = 1/cosθ]`

= `(1 + tan^2"A")^2 - (sin^4"A")/(cos^4"A") - 2 tan^2"A"  ...[1 + tan^2θ = sec^2θ]`

= `1^2 + 2 xx 1 xx  tan^2"A" + (tan^2"A")^2 - tan^4"A" - 2tan^2"A"   ...[(a + b)^2 = a^2 + 2ab + b^2 tanθ = (sinθ)/(cosθ)]`

= `1 + cancel(2tan^2"A") + cancel(tan^4"A") - cancel(tan^4"A") - cancel(2tan^2"A")`

= 1

= R.H.S

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Application of Trigonometry
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 6: Trigonometry - Practice Set 6.1 [पृष्ठ १३१]

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बालभारती Geometry (Mathematics 2) [English] 10 Standard SSC Maharashtra State Board
पाठ 6 Trigonometry
Practice Set 6.1 | Q 6.11 | पृष्ठ १३१

संबंधित प्रश्‍न

If \[\tan \theta = \frac{3}{4}\], find the values of sec​θ and cos​θ


Prove that:

cos2θ (1 + tan2θ)


Prove that:

(secθ - cosθ)(cotθ + tanθ) = tanθ.secθ.


Prove that:

\[\cot\theta + \tan\theta = cosec\theta \sec\theta\]

Prove that:

\[\sec\theta + \tan\theta = \frac{\cos\theta}{1 - \sin\theta}\]

Prove that:
If \[\tan\theta + \frac{1}{\tan\theta} = 2\], then show that \[\tan^2 \theta + \frac{1}{\tan^2 \theta} = 2\]


Choose the correct alternative answer for the following question.

1 + tan2 \[\theta\]  = ?


Choose the correct alternative answer for the following question.

When we see at a higher level, from the horizontal line, angle formed is ........
 

Prove the following.
sec2θ + cosec2θ = sec2θ × cosec2θ 


Prove the following.
cot2θ – tan2θ = cosec2θ – sec2θ


Prove the following.

\[\frac{1}{1 - \sin\theta} + \frac{1}{1 + \sin\theta} = 2 \sec^2 \theta\]

Prove the following.

\[\frac{\tan\theta}{\sec\theta + 1} = \frac{\sec\theta - 1}{\tan\theta}\]


Prove the following.

\[\frac{\tan^3 \theta - 1}{\tan\theta - 1} = \sec^2 \theta + \tan\theta\]

Choose the correct alternative: 
sinθ × cosecθ =?


If sinθ = `8/17`, where θ is an acute angle, find the value of cos θ by using identities.


Prove that: (sec θ – cos θ) (cot θ + tan θ) = tan θ.sec θ

Proof: L.H.S. = (sec θ – cos θ) (cot θ + tan θ)

= `(1/square - cos θ) (square/square + square/square)` ......`[∵ sec θ = 1/square, cot θ = square/square and tan θ = square/square]`

= `((1 - square)/square) ((square + square)/(square  square))`

= `square/square xx 1/(square  square)`  ......`[(∵ square + square = 1),(∴ square = 1 - square)]`

 = `square/(square  square)`

= tan θ.sec θ

= R.H.S.

∴ L.H.S. = R.H.S.

∴ (sec θ – cos θ) (cot θ + tan θ) = tan θ.sec θ


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