English

Prove the following. secθ (1 – sinθ) (secθ + tanθ) = 1 - Geometry Mathematics 2

Advertisements
Advertisements

Question

Prove the following.

secθ (1 – sinθ) (secθ + tanθ) = 1

Sum

Solution

secθ (1 – sinθ)(secθ + tanθ) = 1

LHS = secθ (1 – sinθ)(secθ + tanθ)

LHS = (secθ – secθ sinθ)(secθ + tanθ)

`"LHS" = (secθ  –  1/cosθ × sinθ)(secθ + tanθ)`

`"LHS" = (secθ  –  sinθ/cosθ)(secθ + tanθ)`

`"LHS" = (secθ  –  tan θ)(secθ + tanθ)  ...[(a + b)(a - b) = a^2 - b^2]`

`"LHS" = sec^2θ  –  tan^2θ      ...{(1 + tan^2θ = sec^2θ),(∴ sec^2θ − tan^2θ = 1):}`

LHS = 1

RHS = 1

LHS = RHS

Hence proved.

shaalaa.com
Application of Trigonometry
  Is there an error in this question or solution?
Chapter 6: Trigonometry - Problem Set 6 [Page 138]

RELATED QUESTIONS

If \[\sin\theta = \frac{7}{25}\], find the values of cosθ and tan​θ.


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


If \[\cot\theta = \frac{40}{9}\], find the values of cosecθ and sinθ.


If 5 secθ – 12 cosecθ = 0, find the values of secθ, cosθ, and sinθ.


Prove that:

cos2θ (1 + tan2θ)


Prove that:

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

Prove that:

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


Prove that: `1/"sec θ − tan θ" = "sec θ + tan θ"`


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


Prove that:

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

Choose the correct alternative answer for the following question.
sin \[\theta\] cosec \[\theta\]= ?


Prove the following.
sec2θ + cosec2θ = sec2θ × cosec2θ 


Prove the following.

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


Show that: 

`sqrt((1-cos"A")/(1+cos"A"))=cos"ecA - cotA"`


ΔAMT∼ΔAHE, construct Δ AMT such that MA = 6.3 cm, ∠MAT=120°, AT = 4.9 cm and `"MA"/"HA"=7/5`, then construct ΔAHE.


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×