मराठी

If M Sin θ = N Sin ( θ + 2 α ) , Prove that Tan ( θ + α ) Cot α = M + N M − N - Mathematics

Advertisements
Advertisements

प्रश्न

If \[m \sin\theta = n \sin\left( \theta + 2\alpha \right)\], prove that \[\tan\left( \theta + \alpha \right) \cot\alpha = \frac{m + n}{m - n}\]

बेरीज

उत्तर

Given:
\[m \sin\theta = n \sin\left( \theta + 2\alpha \right)\] 

\[\Rightarrow \frac{m}{n} = \frac{\sin\left( \theta + 2\alpha \right)}{\sin\theta}\]
Applying componendo and dividendo, we get

\[\frac{m + n}{m - n} = \frac{\sin\left( \theta + 2\alpha \right) + \sin\theta}{\sin\left( \theta + 2\alpha \right) - \sin\theta}\]

\[ \Rightarrow \frac{m + n}{m - n} = \frac{2\sin\left( \frac{\theta + 2\alpha + \theta}{2} \right)\cos\left( \frac{\theta + 2\alpha - \theta}{2} \right)}{2\sin\left( \frac{\theta + 2\alpha - \theta}{2} \right)\cos\left( \frac{\theta + 2\alpha + \theta}{2} \right)}\]

\[ \Rightarrow \frac{m + n}{m - n} = \frac{\sin\left( \theta + \alpha \right) \cos\alpha}{\sin\alpha \cos\left( \theta + \alpha \right)}\]

\[ \Rightarrow \frac{m + n}{m - n} = \tan\left( \theta + \alpha \right) \cot\alpha\]

\[\therefore \tan\left( \theta + \alpha \right) \cot\alpha = \frac{m + n}{m - n}\]
shaalaa.com
Transformation Formulae
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 8: Transformation formulae - Exercise 8.2 [पृष्ठ १९]

APPEARS IN

आरडी शर्मा Mathematics [English] Class 11
पाठ 8 Transformation formulae
Exercise 8.2 | Q 19 | पृष्ठ १९

संबंधित प्रश्‍न

Prove that:

\[2\sin\frac{5\pi}{12}\sin\frac{\pi}{12} = \frac{1}{2}\]

 


Prove that:

\[2\cos\frac{5\pi}{12}\cos\frac{\pi}{12} = \frac{1}{2}\]

Show that :

\[\sin 50^\circ \cos 85^\circ = \frac{1 - \sqrt{2} \sin 35^\circ}{2\sqrt{2}}\]

Prove that:
cos 40° cos 80° cos 160° = \[- \frac{1}{8}\]

 


Prove that:
cos 20° cos 40° cos 80° = \[\frac{1}{8}\]

 


Show that:
sin A sin (B − C) + sin B sin (C − A) + sin C sin (A − B) = 0


Express each of the following as the product of sines and cosines:
 cos 12x - cos 4x


Prove that:
sin 50° + sin 10° = cos 20°


Prove that:
sin 105° + cos 105° = cos 45°


Prove that:
 cos 55° + cos 65° + cos 175° = 0


Prove that:
\[\sin\frac{5\pi}{18} - \cos\frac{4\pi}{9} = \sqrt{3} \sin\frac{\pi}{9}\]


Prove that:

\[\cos\frac{\pi}{12} - \sin\frac{\pi}{12} = \frac{1}{\sqrt{2}}\]

 


Prove that:

sin 51° + cos 81° = cos 21°

Prove that:
cos 3A + cos 5A + cos 7A + cos 15A = 4 cos 4A cos 5A cos 6A


Prove that:
\[\sin\frac{x}{2}\sin\frac{7x}{2} + \sin\frac{3x}{2}\sin\frac{11x}{2} = \sin 2x \sin 5x .\]

 


Prove that:

\[\frac{\sin A + \sin 3A}{\cos A - \cos 3A} = \cot A\]

 


Prove that:

\[\frac{\sin 9A - \sin 7A}{\cos 7A - \cos 9A} = \cot 8A\]

Prove that:

\[\frac{\sin 3A \cos 4A - \sin A \cos 2A}{\sin 4A \sin A + \cos 6A \cos A} = \tan 2A\]

Prove that:

\[\frac{\sin A \sin 2A + \sin 3A \sin 6A}{\sin A \cos 2A + \sin 3A \cos 6A} = \tan 5A\]

Prove that:
cos (A + B + C) + cos (A − B + C) + cos (A + B − C) + cos (− A + B + C) = 4 cos A cos Bcos C


Prove that:

\[\frac{\cos (A + B + C) + \cos ( - A + B + C) + \cos (A - B + C) + \cos (A + B - C)}{\sin (A + B + C) + \sin ( - A + B + C) + \sin (A - B + C) - \sin (A + B - C)} = \cot C\]

Write the value of \[\sin\frac{\pi}{15}\sin\frac{4\pi}{15}\sin\frac{3\pi}{10}\]


If sin 2A = λ sin 2B, then write the value of \[\frac{\lambda + 1}{\lambda - 1}\]


cos 40° + cos 80° + cos 160° + cos 240° =


sin 163° cos 347° + sin 73° sin 167° =


If sin x + sin y = \[\sqrt{3}\] (cos y − cos x), then sin 3x + sin 3y =

 


Express the following as the sum or difference of sine or cosine:

`sin  "A"/8  sin  (3"A")/8`


Express the following as the product of sine and cosine.

cos 2A + cos 4A


Prove that:

sin A sin(60° + A) sin(60° – A) = `1/4` sin 3A


Prove that:

2 cos `pi/13` cos \[\frac{9\pi}{13} + \text{cos} \frac{3\pi}{13} + \text{cos} \frac{5\pi}{13}\] = 0


Evaluate-

cos 20° + cos 100° + cos 140°


If cos A + cos B = `1/2` and sin A + sin B = `1/4`, prove that tan `(("A + B")/2) = 1/2`


If secx cos5x + 1 = 0, where 0 < x ≤ `pi/2`, then find the value of x.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×