हिंदी

Prove the identity (sin θ + cos θ)(tan θ + cot θ) = sec θ + cosec θ.

Advertisements
Advertisements

प्रश्न

Prove the identity (sin θ + cos θ)(tan θ + cot θ) = sec θ + cosec θ.

योग
Advertisements

उत्तर

L.H.S. = (sin θ + cos θ)(tan θ + cot θ)

= `(sin theta + cos theta)(sin theta/cos theta + costheta/sin theta)`

= `(sin theta + cos theta)((sin^2 theta + cos^2 theta)/(costhetasin theta))`

= `(sintheta+costheta)xx1/(sinthetacostheta)`   ...[∵ sin2θ + cos2θ = 1]

= `(sin theta + cos theta)/(cos theta sin theta)`

= `sin theta/(cos thetasin theta) + cos theta/(cos theta sin theta)`

= `1/cos theta + 1/sin theta`

= `sec theta + cosec  theta`

= R.H.S

Hence proved.

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
अध्याय 21: Trigonometrical Identities - Exercise 21 (E) [पृष्ठ ३३३]

APPEARS IN

सेलिना Concise Mathematics [English] Class 10 ICSE
अध्याय 21 Trigonometrical Identities
Exercise 21 (E) | Q 15. | पृष्ठ ३३३

संबंधित प्रश्न

 

If `sec alpha=2/sqrt3`  , then find the value of `(1-cosecalpha)/(1+cosecalpha)` where α is in IV quadrant.

 

Prove the following trigonometric identities:

`(\text{i})\text{ }\frac{\sin \theta }{1-\cos \theta }=\text{cosec}\theta+\cot \theta `


If (secA + tanA)(secB + tanB)(secC + tanC) = (secA – tanA)(secB – tanB)(secC – tanC) prove that each of the side is equal to ±1. We have,


Prove the following trigonometric identities.

`tan theta + 1/tan theta` = sec θ.cosec θ


Prove the following trigonometric identities.

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


Prove the following trigonometric identities.

`(tan^3 theta)/(1 + tan^2 theta) + (cot^3 theta)/(1 + cot^2 theta) = sec theta cosec theta - 2 sin theta cos theta`


Prove the following trigonometric identities.

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


`sqrt((1-cos theta)/(1+cos theta)) = (cosec  theta - cot  theta)`


Write the value of ` sec^2 theta ( 1+ sintheta )(1- sintheta).`


What is the value of \[\frac{\tan^2 \theta - \sec^2 \theta}{\cot^2 \theta - {cosec}^2 \theta}\]


sec4 A − sec2 A is equal to


If x = r sin θ cos ϕ, y = r sin θ sin ϕ and z = r cos θ, then 


If x = a sec θ cos ϕ, y = b sec θ sin ϕ and z = c tan θ, then\[\frac{x^2}{a^2} + \frac{y^2}{b^2}\]


Prove the following identity : 

`(cos^3A + sin^3A)/(cosA + sinA) + (cos^3A - sin^3A)/(cosA - sinA) = 2`


Without using trigonometric table , evaluate : 

`cosec49°cos41° + (tan31°)/(cot59°)`


Verify that the points A(–2, 2), B(2, 2) and C(2, 7) are the vertices of a right-angled triangle. 


1 + cot2θ = ? 


If `sec θ = 41/40`, then find values of sin θ, cot θ, cosec θ.


Prove that `(tan(90 - θ) + cot(90 - θ))/("cosec"  θ) = sec θ`.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×