हिंदी

Prove the Following Trigonometric Identities. (Sec^2 θ − 1) (Cosec^2 θ − 1) = 1

Advertisements
Advertisements

प्रश्न

Prove the following trigonometric identities.

(sec2 θ − 1) (cosec2 θ − 1) = 1

Prove the following:

(sec2 θ − 1) (cosec2 θ − 1) = 1

प्रमेय
Advertisements

उत्तर

We know that

sec2 θ − tan2 θ = 1

cosec2 θ − cot2 θ = 1

So,

(sec2 θ − 1)(cosec2 θ − 1) = tan2 θ × cot2 θ

= (tan θ × cot θ)

= `(tan θ xx 1/tan θ)^2`

= (1)2

= 1

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 18: Trigonometric identities - Exercise 18A [पृष्ठ ४२३]

APPEARS IN

नूतन Mathematics [English] Class 10 ICSE
अध्याय 18 Trigonometric identities
Exercise 18A | Q 2. | पृष्ठ ४२३

संबंधित प्रश्न

If acosθ – bsinθ = c, prove that asinθ + bcosθ = `\pm \sqrt{a^{2}+b^{2}-c^{2}`


Prove that `(sin theta)/(1-cottheta) + (cos theta)/(1 - tan theta) = cos theta + sin theta`


Prove the following trigonometric identities.

`"cosec" theta sqrt(1 - cos^2 theta) = 1`


Prove the following trigonometric identities.

tan2 θ − sin2 θ = tan2 θ sin2 θ


Prove the following trigonometric identity.

`(sin theta - cos theta + 1)/(sin theta + cos theta - 1) = 1/(sec theta - tan theta)`


Prove the following identities:

cosec A(1 + cos A) (cosec A – cot A) = 1


Prove the following identities:

sec2A + cosec2A = sec2A . cosec2A


Prove the following identities:

`1/(sinA + cosA) + 1/(sinA - cosA) = (2sinA)/(1 - 2cos^2A)`


Prove the following identities:

cosec4 A (1 – cos4 A) – 2 cot2 A = 1


`(1+tan^2theta)(1+cot^2 theta)=1/((sin^2 theta- sin^4theta))`


Write the value of `(1 + tan^2 theta ) cos^2 theta`. 


Write the value of `(1 + cot^2 theta ) sin^2 theta`. 


Write the value of tan1° tan 2°   ........ tan 89° .


Write the value of cosec2 (90° − θ) − tan2 θ. 


9 sec2 A − 9 tan2 A is equal to


If sin θ − cos θ = 0 then the value of sin4θ + cos4θ


Prove the following identity : 

`cosA/(1 - tanA) + sinA/(1 - cotA) = sinA + cosA`


Prove the following identities:

`(sec"A"-1)/(sec"A"+1)=(sin"A"/(1+cos"A"))^2`


Prove that `sinA/sin(90^circ - A) + cosA/cos(90^circ - A) = sec(90^circ - A) cosec(90^circ - A)`


Without using trigonometric identity , show that :

`sec70^circ sin20^circ - cos20^circ cosec70^circ = 0`


Find A if tan 2A = cot (A-24°).


Prove that cot θ. tan (90° - θ) - sec (90° - θ). cosec θ + 1 = 0.


Prove that sec2 (90° - θ) + tan2 (90° - θ) = 1 + 2 cot2 θ.


If cot θ + tan θ = x and sec θ – cos θ = y, then prove that `(x^2y)^(2/3) – (xy^2)^(2/3)` = 1


Choose the correct alternative:

sec2θ – tan2θ =?


Prove that cot2θ – tan2θ = cosec2θ – sec2θ 


Prove that

sin2A . tan A + cos2A . cot A + 2 sin A . cos A = tan A + cot A


`sqrt((1 - cos^2theta) sec^2 theta) = tan theta` 


Complete the following activity to prove:

cotθ + tanθ = cosecθ × secθ

Activity: L.H.S. = cotθ + tanθ

= `cosθ/sinθ + square/cosθ`

= `(square + sin^2theta)/(sinθ xx cosθ)`

= `1/(sinθ xx  cosθ)` ....... ∵ `square`

= `1/sinθ xx 1/cosθ`

= `square xx secθ`

∴ L.H.S. = R.H.S.


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×