English

Evaluate : ∫π0 (4x sin x)/(1+cos2 x) dx - Mathematics

Advertisements
Advertisements

Question

Evaluate :

`∫_0^π(4x sin x)/(1+cos^2 x) dx`

Advertisements

Solution

`∫_0^π(4x sin x)/(1+cos^2 x) dx..................(1)`

Using f (x) = f (ax), we get:

`I=∫_0^π(4(pi-x) sin x)/(1+cos^2 x) dx .....................(2)`

Adding (1) and (2), we get:

`2I=4int_0^pi(pi sinx)/(1+cos^2x)dx`

`I=2int_0^pi(pi sinx)/(1+cos^2x)dx`

Let cos x=t.

sin xdx=dt

`⇒I=2π∫_1^(−1)−1/(1+t^2)dt`

`=>I=-2pi tan^(-1) t_1^(-1)`

`=>I=-2pi(-pi/4-pi/4)`

`=>I=pi^2`

shaalaa.com
  Is there an error in this question or solution?
2013-2014 (March) All India Set 1

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

Evaluate : `int1/(3+5cosx)dx`


 

Evaluate `∫_0^(3/2)|x cosπx|dx`

 

Evaluate the integral by using substitution.

`int_0^1 x/(x^2 +1)`dx


Evaluate the integral by using substitution.

`int_0^2 dx/(x + 4 - x^2)`


`int 1/(1 + cos x)` dx = _____

A) `tan(x/2) + c`

B) `2 tan (x/2) + c`

C) -`cot (x/2) + c`

D) -2 `cot (x/2)` + c


Evaluate `int_0^(pi/4) (sinx + cosx)/(16 + 9sin2x) dx`


Evaluate of the following integral:

(i)  \[\int x^4 dx\]

 


Evaluate: 

\[\int\sqrt{\frac{1 + \cos 2x}{2}}dx\]

Evaluate:

\[\int\sqrt{\frac{1 - \cos 2x}{2}}dx\]

Evaluate: 

\[\int\frac{2 \cos^2 x - \cos 2x}{\cos^2 x}dx\]

Evaluate:

\[\int\frac{e\log \sqrt{x}}{x}dx\]

Evaluate the following integral:

\[\int\limits_0^2 \left| x^2 - 3x + 2 \right| dx\]

 


Evaluate the following integral:

\[\int\limits_0^3 \left| 3x - 1 \right| dx\]

 


Evaluate the following integral:

\[\int\limits_{- \pi/2}^{\pi/2} \left\{ \sin \left| x \right| + \cos \left| x \right| \right\} dx\]

 


Evaluate the following integral:

\[\int\limits_{- 5}^0 f\left( x \right) dx, where\ f\left( x \right) = \left| x \right| + \left| x + 2 \right| + \left| x + 5 \right|\]

 


Evaluate the following integral:

\[\int\limits_0^4 \left( \left| x \right| + \left| x - 2 \right| + \left| x - 4 \right| \right) dx\]

Evaluate each of the following integral:

\[\int_{- \frac{\pi}{3}}^\frac{\pi}{3} \frac{1}{1 + e^\ tan\ x}dx\]

 


Evaluate each of the following integral:

\[\int_{- \frac{\pi}{4}}^\frac{\pi}{4} \frac{x^{11} - 3 x^9 + 5 x^7 - x^5 + 1}{\cos^2 x}dx\]

\[\int\limits_0^a \frac{\sqrt{x}}{\sqrt{x} + \sqrt{a - x}} dx\]

Evaluate the following integral:

\[\int_0^\frac{\pi}{2} \frac{\tan^7 x}{\tan^7 x + \cot^7 x}dx\]

Evaluate 

\[\int\limits_0^\pi \frac{x}{1 + \sin \alpha \sin x}dx\]


Evaluate : 

\[\int\limits_0^{3/2} \left| x \sin \pi x \right|dx\]

Evaluate : \[\int\limits_{- 2}^1 \left| x^3 - x \right|dx\] .


Evaluate: `int_-π^π (1 - "x"^2) sin "x" cos^2 "x"  d"x"`.


Evaluate: `int_1^5{|"x"-1|+|"x"-2|+|"x"-3|}d"x"`.


`int_(pi/5)^((3pi)/10) [(tan x)/(tan x + cot x)]`dx = ?


Evaluate the following:

`int ("e"^(6logx) - "e"^(5logx))/("e"^(4logx) - "e"^(3logx)) "d"x`


The value of `int_0^1 (x^4(1 - x)^4)/(1 + x^2) dx` is


If `int x^5 cos (x^6)dx = k sin (x^6) + C`, find the value of k.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×