मराठी

Prove That: 1 Sin ( X − a ) Cos ( X − B ) = Cot ( X − a ) + Tan ( X − B ) Cos ( a − B )

Advertisements
Advertisements

प्रश्न

Prove that:

\[\frac{1}{\sin \left( x - a \right) \cos \left( x - b \right)} = \frac{\cot \left( x - a \right) + \tan \left( x - b \right)}{\cos \left( a - b \right)}\]

 

थोडक्यात उत्तर
Advertisements

उत्तर

\[\text{ RHS }= \frac{\cot(x - a) + \tan(x - b)}{\cos(a - b)} \]
\[ = \frac{\frac{\cos(x - a)}{\sin(x - a)} + \frac{\sin(x - b)}{\cos(x - b)}}{\cos(a - b)}\]
\[ = \frac{\cos(x - b) \cos(x - a) + \sin(x - a) \sin(x - b)}{\cos(a - b) \sin(x - a) \cos(x - b)}\]
\[ = \frac{\cos(x - b - x + a)}{\cos(a - b) \sin(x - a) \cos(x - b)} (\text{ Using }\cos(A - B) = \cos A \cos b B + \sin A \sin B)\]
\[ = \frac{\cos(a - b)}{\cos(a - b) \sin(x - a) \cos(x - b)}\]
\[ = \frac{1}{\sin(x - a) \cos(x - b)} \]
= RHS
Hence proved .

 

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 7: Values of Trigonometric function at sum or difference of angles - Exercise 7.1 [पृष्ठ २१]

APPEARS IN

आर.डी. शर्मा Mathematics [English] Class 11
पाठ 7 Values of Trigonometric function at sum or difference of angles
Exercise 7.1 | Q 29.2 | पृष्ठ २१

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्‍न

Prove that  `cot^2  pi/6 + cosec  (5pi)/6 + 3 tan^2  pi/6 = 6`


Prove that: `2 sin^2  (3pi)/4 + 2 cos^2  pi/4  + 2 sec^2  pi/3 = 10`


Find the value of: sin 75°


Prove the following: `cos (pi/4 xx x) cos (pi/4 - y) - sin (pi/4 -  x)sin (pi/4  - y) =  sin (x + y)`


Prove the following:

`cos ((3pi)/ 2 + x ) cos(2pi + x) [cot ((3pi)/2 - x) + cot (2pi + x)]= 1`


Prove the following:

sin (n + 1)x sin (n + 2)x + cos (n + 1)x cos (n + 2)x = cos x


Prove the following:

`cos ((3pi)/4 + x) - cos((3pi)/4 - x) = -sqrt2 sin x`


Prove the following:

sin 2x + 2sin 4x + sin 6x = 4cos2 x sin 4x


Prove the following:

`(cos9x - cos5x)/(sin17x - sin 3x) = - (sin2x)/(cos 10x)`


Prove the following:

`(sin 5x + sin 3x)/(cos 5x + cos 3x) = tan 4x`


Prove the following:

cos 6x = 32 cos6 x – 48 cos4 x + 18 cos2 x – 1


Prove that: `(cos x - cosy)^2 + (sin x - sin y)^2 = 4 sin^2  (x - y)/2`


Prove that: sin 3x + sin 2x – sin x = 4sin x `cos  x/2 cos  (3x)/2`


Evaluate the following:
sin 78° cos 18° − cos 78° sin 18°


Prove that:

\[\frac{\sin \left( A - B \right)}{\sin A \sin B} + \frac{\sin \left( B - C \right)}{\sin B \sin C} + \frac{\sin \left( C - A \right)}{\sin C \sin A} = 0\]

 


Prove that:
\[\tan\frac{\pi}{12} + \tan\frac{\pi}{6} + \tan\frac{\pi}{12}\tan\frac{\pi}{6} = 1\]


If tan x + \[\tan \left( x + \frac{\pi}{3} \right) + \tan \left( x + \frac{2\pi}{3} \right) = 3\], then prove that \[\frac{3 \tan x - \tan^3 x}{1 - 3 \tan^2 x} = 1\].


If angle \[\theta\]  is divided into two parts such that the tangents of one part is \[\lambda\] times the tangent of other, and \[\phi\] is their difference, then show that\[\sin\theta = \frac{\lambda + 1}{\lambda - 1}\sin\phi\]

 

Find the maximum and minimum values of each of the following trigonometrical expression:

 12 sin x − 5 cos x 


Reduce each of the following expressions to the sine and cosine of a single expression: 

cos x − sin x 


Write the maximum and minimum values of 3 cos x + 4 sin x + 5. 


If A + B + C = π, then sec A (cos B cos C − sin B sin C) is equal to


If A + B + C = π, then \[\frac{\tan A + \tan B + \tan C}{\tan A \tan B \tan C}\] is equal to

 

If \[\cos P = \frac{1}{7}\text{ and }\cos Q = \frac{13}{14}\], where P and Q both are acute angles. Then, the value of P − Q is

 


If tan (A − B) = 1 and sec (A + B) = \[\frac{2}{\sqrt{3}}\], the smallest positive value of B is

 

If \[\tan\alpha = \frac{x}{x + 1}\] and \[\tan\alpha = \frac{x}{x + 1}\], then \[\alpha + \beta\] is equal to


Express the following as the sum or difference of sines and cosines:
2 cos 3x sin 2xa


Find the most general value of θ satisfying the equation tan θ = –1 and cos θ = `1/sqrt(2)`.


If cotθ + tanθ = 2cosecθ, then find the general value of θ.


If cos(θ + Φ) = m cos(θ – Φ), then prove that 1 tan θ = `(1 - m)/(1 + m) cot phi`

[Hint: Express `(cos(theta + Φ))/(cos(theta - Φ)) = m/1` and apply Componendo and Dividendo]


The value of tan 75° - cot 75° is equal to ______.


If tanα = `m/(m +  1)`, tanβ = `1/(2m + 1)`, then α + β is equal to ______.


The value of `cot(pi/4 + theta)cot(pi/4 - theta)` is ______.


If tanα = `1/7`, tanβ = `1/3`, then cos2α is equal to ______.


If sinx + cosx = a, then sin6x + cos6x = ______.


The maximum distance of a point on the graph of the function y = `sqrt(3)` sinx + cosx from x-axis is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×