English

Prove that (Sinθ - Cosθ + 1)/(Sinθ + Cosθ - 1) = 1/(Secθ - Tanθ) - Mathematics

Advertisements
Advertisements

Question

Prove that `(sinθ - cosθ + 1)/(sinθ + cosθ - 1) = 1/(secθ - tanθ)`

Sum
Advertisements

Solution

LHS = `(sinθ - cosθ + 1)/(sinθ + cosθ - 1)`

LHS = `((sinθ - cosθ + 1)/(sinθ + cosθ - 1)) xx ((sinθ + cosθ + 1)/(sinθ + cosθ + 1))`

LHS = `((sinθ + 1 - cosθ )/(sinθ + cosθ - 1)) xx ((sinθ + 1 + cosθ)/(sinθ + cosθ + 1))`

LHS = `((sinθ + 1)^2 - cos^2θ)/((sinθ + cosθ)^2 - 1^2)`

LHS = `(sin^2θ + 1 + 2sinθ - cos^2θ)/(sin^2θ + cos^2θ + 2sinθcosθ - 1)`
 
LHS = `(1 - cos^2θ + 1 + 2sinθ - cos^2θ)/(1 + 2sinθcosθ - 1)   ...(sin^2θ + cos^2θ = 1)`
 
LHS = `(2 - 2cos^2θ + 2sinθ)/( 2sinθcosθ)`
 
LHS = `[cancel2(1 - cos^2θ + sinθ)]/[cancel2(sinθcosθ)]`
 
LHS = `( 1 - cos^2θ + sinθ)/(sinθcosθ)`
 
LHS = `(sin^2θ + sinθ)/( sinθcosθ )`
 
LHS = `(sinθ + 1)/cosθ`
 
LHS = `1/cosθ + sinθ/cosθ`
 
LHS = secθ + tanθ
 
LHS = `( secθ + tanθ ) xx (secθ - tanθ)/(secθ - tanθ)`
 
LHS = `(sec^2θ - tan^2θ)/(secθ - tanθ)`
 
LHS =`1/(secθ- tanθ)      ...[∴ sec^2θ − tan^2θ = 1]`
 
RHS = `1/(secθ- tanθ)`
 
LHS = RHS
 
Hence, it proved.
shaalaa.com
  Is there an error in this question or solution?
Chapter 6: Trigonometry - Problem Set 6 [Page 138]

RELATED QUESTIONS

If secθ + tanθ = p, show that `(p^{2}-1)/(p^{2}+1)=\sin \theta`


Prove the following trigonometric identities.

`(cot A - cos A)/(cot A + cos A) = (cosec A - 1)/(cosec A + 1)`


Prove the following trigonometric identities.

(1 + cot A − cosec A) (1 + tan A + sec A) = 2


Prove the following identities:

`(sec A - 1)/(sec A + 1) = (1 - cos A)/(1 + cos A)`


Prove the following identities:

cosec4 A (1 – cos4 A) – 2 cot2 A = 1


`(1 + cot^2 theta ) sin^2 theta =1`


If `cosec  theta = 2x and cot theta = 2/x ," find the value of"  2 ( x^2 - 1/ (x^2))`


If x = a sin θ and y = b cos θ, what is the value of b2x2 + a2y2?


What is the value of \[6 \tan^2 \theta - \frac{6}{\cos^2 \theta}\]


If a cos θ + b sin θ = 4 and a sin θ − b sin θ = 3, then a2 + b2


9 sec2 A − 9 tan2 A is equal to


Prove the following Identities :

`(cosecA)/(cotA+tanA)=cosA`


Prove the following identity : 

`sqrt((secq - 1)/(secq + 1)) + sqrt((secq + 1)/(secq - 1))` = 2 cosesq


Prove the following identity  :

`(1 + cotA)^2 + (1 - cotA)^2 = 2cosec^2A`


If x = acosθ , y = bcotθ , prove that `a^2/x^2 - b^2/y^2 = 1.`


Choose the correct alternative:

1 + tan2 θ = ?


A moving boat is observed from the top of a 150 m high cliff moving away from the cliff. The angle of depression of the boat changes from 60° to 45° in 2 minutes. Find the speed of the boat in m/min.


Prove that `((1 - cos^2 θ)/cos θ)((1 - sin^2θ)/(sin θ)) = 1/(tan θ + cot θ)`


If sin θ + cos θ = `sqrt(3)`, then prove that tan θ + cot θ = 1.


If sin θ (1 + sin2 θ) = cos2 θ, then prove that cos6 θ – 4 cos4 θ + 8 cos2 θ = 4


(sec θ + tan θ) . (sec θ – tan θ) = ?


Prove that `"cot A"/(1 - cot"A") + "tan A"/(1 - tan "A")` = – 1


Prove that cosec θ – cot θ = `sin theta/(1 + cos theta)`


Prove that 2(sin6A + cos6A) – 3(sin4A + cos4A) + 1 = 0


Prove that `"cot A"/(1 - tan "A") + "tan A"/(1 - cot"A")` = 1 + tan A + cot A = sec A . cosec A + 1


If tan θ – sin2θ = cos2θ, then show that sin2 θ = `1/2`.


If sinθ – cosθ = 0, then the value of (sin4θ + cos4θ) is ______.


If `sqrt(3) tan θ` = 1, then find the value of sin2θ – cos2θ.


Which of the following is true for all values of θ (0° ≤ θ ≤ 90°)?


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×