English

1 + Cos X 1 − Cos X is Equal to

Advertisements
Advertisements

Question

\[\sqrt{\frac{1 + \cos x}{1 - \cos x}}\] is equal to

 

Options

  • cosec x + cot x

  • cosec x − cot x

  • −cosec x + cot x

  • −cosec x − cot x

MCQ
Advertisements

Solution

−cosec x − cot x
\[\sqrt{\frac{1 + \cos x}{1 - \cos x}} \]
\[ = \sqrt{\frac{\left( 1 + \cos x \right)\left( 1 + \cos x \right)}{\left( 1 - \cos x \right)\left( 1 + \cos x \right)}}\]
\[ = \sqrt{\frac{\left( 1 + \cos x \right)^2}{1 - \cos^2 x}}\]
\[ = \sqrt{\frac{\left( 1 + \cos x \right)^2}{\sin^2 x}}\]
\[ = \frac{\left( 1 + \cos x \right)}{- \sin x} \left[\text{ as, }\pi < x < 2\pi,\text{ so }\sin x\text{ will be negative }\right]\]
\[ = - \left( cosec x + \cot x \right) \]
\[ = - cosec x - \cot x\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 5: Trigonometric Functions - Exercise 5.5 [Page 41]

APPEARS IN

R.D. Sharma Mathematics [English] Class 11
Chapter 5 Trigonometric Functions
Exercise 5.5 | Q 4 | Page 41

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Find the principal and general solutions of the equation  `cot x = -sqrt3`


Find the general solution of the equation cos 4 x = cos 2 x


Find the general solution for each of the following equations sec2 2x = 1– tan 2x


If \[T_n = \sin^n x + \cos^n x\], prove that \[\frac{T_3 - T_5}{T_1} = \frac{T_5 - T_7}{T_3}\]

 


If \[T_n = \sin^n x + \cos^n x\], prove that  \[2 T_6 - 3 T_4 + 1 = 0\]


Prove that:  tan 225° cot 405° + tan 765° cot 675° = 0


Prove that:
\[\sin^2 \frac{\pi}{18} + \sin^2 \frac{\pi}{9} + \sin^2 \frac{7\pi}{18} + \sin^2 \frac{4\pi}{9} = 2\]

 

Prove that:
\[\sec\left( \frac{3\pi}{2} - x \right)\sec\left( x - \frac{5\pi}{2} \right) + \tan\left( \frac{5\pi}{2} + x \right)\tan\left( x - \frac{3\pi}{2} \right) = - 1 .\]


If \[\frac{\pi}{2} < x < \frac{3\pi}{2},\text{ then }\sqrt{\frac{1 - \sin x}{1 + \sin x}}\] is equal to

 


If \[\frac{\pi}{2} < x < \pi, \text{ then }\sqrt{\frac{1 - \sin x}{1 + \sin x}} + \sqrt{\frac{1 + \sin x}{1 - \sin x}}\] is equal to


If tan \[x = - \frac{1}{\sqrt{5}}\] and θ lies in the IV quadrant, then the value of cos x is

 

The value of sin25° + sin210° + sin215° + ... + sin285° + sin290° is


sin2 π/18 + sin2 π/9 + sin2 7π/18 + sin2 4π/9 =


If A lies in second quadrant 3tan A + 4 = 0, then the value of 2cot A − 5cosA + sin A is equal to


Find the general solution of the following equation:

\[\sec x = \sqrt{2}\]

Find the general solution of the following equation:

\[\tan x = - \frac{1}{\sqrt{3}}\]

Find the general solution of the following equation:

\[\tan mx + \cot nx = 0\]

Find the general solution of the following equation:

\[\sin 2x + \cos x = 0\]

Solve the following equation:

\[2 \cos^2 x - 5 \cos x + 2 = 0\]

Solve the following equation:

\[\cos x \cos 2x \cos 3x = \frac{1}{4}\]

Solve the following equation:

\[\tan 3x + \tan x = 2\tan 2x\]

Solve the following equation:

\[\sin x + \cos x = 1\]

Solve the following equation:
\[\cot x + \tan x = 2\]

 


Write the number of solutions of the equation tan x + sec x = 2 cos x in the interval [0, 2π].


Write the number of solutions of the equation
\[4 \sin x - 3 \cos x = 7\]


Write the set of values of a for which the equation

\[\sqrt{3} \sin x - \cos x = a\] has no solution.

Write the values of x in [0, π] for which \[\sin 2x, \frac{1}{2}\]

 and cos 2x are in A.P.


If \[2 \sin^2 x = 3\cos x\]. where \[0 \leq x \leq 2\pi\], then find the value of x.


The general value of x satisfying the equation
\[\sqrt{3} \sin x + \cos x = \sqrt{3}\]


Find the principal solution and general solution of the following:
cot θ = `sqrt(3)`


Solve the following equations for which solution lies in the interval 0° ≤ θ < 360°

sin4x = sin2x


Solve the following equations:
sin 2θ – cos 2θ – sin θ + cos θ = θ


Solve the following equations:
`sin theta + sqrt(3) cos theta` = 1


Solve the following equations:
`tan theta + tan (theta + pi/3) + tan (theta + (2pi)/3) = sqrt(3)`


Solve the following equations:
2cos 2x – 7 cos x + 3 = 0


Choose the correct alternative:
If tan α and tan β are the roots of x2 + ax + b = 0 then `(sin(alpha + beta))/(sin alpha sin beta)` is equal to


Choose the correct alternative:
`(cos 6x + 6 cos 4x + 15cos x + 10)/(cos 5x + 5cs 3x + 10 cos x)` is equal to


If sin θ and cos θ are the roots of the equation ax2 – bx + c = 0, then a, b and c satisfy the relation ______.


Find the general solution of the equation sinx – 3sin2x + sin3x = cosx – 3cos2x + cos3x


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×