English

Write the Value of Cos−1 - Mathematics

Advertisements
Advertisements

Question

Write the value of cos−1 \[\left( \cos\frac{5\pi}{4} \right)\]

Advertisements

Solution

\[\cos^{- 1} \left( \cos\frac{5\pi}{4} \right) \neq \frac{5\pi}{4}\]as
\[\frac{5\pi}{4}\]  does not lie between 0 and π
We have
\[\cos^{- 1} \left( \cos\frac{5\pi}{4} \right) = \cos^{- 1} \left\{ \cos\left( 2\pi - \frac{3\pi}{4} \right) \right\}\]
\[ = \cos^{- 1} \left\{ \cos\left( \frac{3\pi}{4} \right) \right\}\]
\[ = \frac{3\pi}{4}\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 4: Inverse Trigonometric Functions - Exercise 4.15 [Page 118]

APPEARS IN

RD Sharma Mathematics [English] Class 12
Chapter 4 Inverse Trigonometric Functions
Exercise 4.15 | Q 30 | Page 118

RELATED QUESTIONS

Solve the following for x :

`tan^(-1)((x-2)/(x-3))+tan^(-1)((x+2)/(x+3))=pi/4,|x|<1`


Solve for x:

`2tan^(-1)(cosx)=tan^(-1)(2"cosec" x)`


`sin^-1(sin  (5pi)/6)`


`sin^-1{(sin - (17pi)/8)}`


`sin^-1(sin4)`


Evaluate the following:

`cos^-1(cos4)`


Evaluate the following:

`tan^-1(tan  (6pi)/7)`


Evaluate the following:

`tan^-1(tan  (9pi)/4)`


Evaluate the following:

`sec^-1(sec  pi/3)`


Evaluate the following:

`sec^-1(sec  (13pi)/4)`


Evaluate the following:

`\text(cosec)^-1(\text{cosec}  pi/4)`


Evaluate the following:

`cot^-1{cot (-(8pi)/3)}`


Evaluate: 

`cot(sin^-1  3/4+sec^-1  4/3)`


Evaluate:

`sin(tan^-1x+tan^-1  1/x)` for x < 0


Evaluate:

`cos(sec^-1x+\text(cosec)^-1x)`,|x|≥1


`sin(sin^-1  1/5+cos^-1x)=1`


Solve the following equation for x:

tan−1(x + 1) + tan−1(x − 1) = tan−1`8/31`


Solve the following equation for x:

tan−1(x −1) + tan−1x tan−1(x + 1) = tan−13x


`sin^-1  63/65=sin^-1  5/13+cos^-1  3/5`


`tan^-1  1/4+tan^-1  2/9=1/2cos^-1  3/2=1/2sin^-1(4/5)`


`2tan^-1(1/2)+tan^-1(1/7)=tan^-1(31/17)`


Prove that

`tan^-1((1-x^2)/(2x))+cot^-1((1-x^2)/(2x))=pi/2`


Find the value of the following:

`cos(sec^-1x+\text(cosec)^-1x),` | x | ≥ 1


Solve the following equation for x:

`cos^-1((x^2-1)/(x^2+1))+1/2tan^-1((2x)/(1-x^2))=(2x)/3`


Write the difference between maximum and minimum values of  sin−1 x for x ∈ [− 1, 1].


If `sin^-1x+sin^-1y+sin^-1z=(3pi)/2,`  then write the value of x + y + z.


What is the value of cos−1 `(cos  (2x)/3)+sin^-1(sin  (2x)/3)?`


Write the value of cos \[\left( 2 \sin^{- 1} \frac{1}{2} \right)\]


If \[\sin^{- 1} \left( \frac{1}{3} \right) + \cos^{- 1} x = \frac{\pi}{2},\] then find x.

 


Write the value of \[\sin^{- 1} \left( \frac{1}{3} \right) - \cos^{- 1} \left( - \frac{1}{3} \right)\]


If x < 0, y < 0 such that xy = 1, then write the value of tan1 x + tan−1 y.


Wnte the value of\[\cos\left( \frac{\tan^{- 1} x + \cot^{- 1} x}{3} \right), \text{ when } x = - \frac{1}{\sqrt{3}}\]


The value of tan \[\left\{ \cos^{- 1} \frac{1}{5\sqrt{2}} - \sin^{- 1} \frac{4}{\sqrt{17}} \right\}\] is

 


If sin−1 − cos−1 x = `pi/6` , then x = 


If \[3\sin^{- 1} \left( \frac{2x}{1 + x^2} \right) - 4 \cos^{- 1} \left( \frac{1 - x^2}{1 + x^2} \right) + 2 \tan^{- 1} \left( \frac{2x}{1 - x^2} \right) = \frac{\pi}{3}\] is equal to

 


It \[\tan^{- 1} \frac{x + 1}{x - 1} + \tan^{- 1} \frac{x - 1}{x} = \tan^{- 1}\]   (−7), then the value of x is

 


Solve for x : {xcos(cot-1 x) + sin(cot-1 x)}= `51/50`


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×