English

Evaluate : ∫x^2/((x^2+2)(2x^2+1))dx

Advertisements
Advertisements

Question

Evaluate : `int x^2/((x^2+2)(2x^2+1))dx` 

Advertisements

Solution

Let` I=int x^2/((x^2+2)(2x^2+1))dx`

consider` x^2/((x^2+2)(2x^2+1))`

Put x2= t (For finding partial fractions only)

`t/((t+2)(2t+1))=A/(t+2)+B/(2t+1)`

t=A(2t+1)+B(t+2)

On Solving we get A=2/3, B=-1/3

`t/((t+2)(2t+1))=(2/3)/(t+2)+(-1/3)/(2t+1)`

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

`I=int[(2/3)/(t+2)+(-1/3)/(2t+1)]dx`

`=2/3int 1/(x^2+2) dx-1/3int 1/(2x^2+1)dx`

`=2/3int 1/(x^2+(sqrt2)^2)dx-1/6int1/(x^2+(1/sqrt2)^2)dx`

`=sqrt2/3 tan^-1 (x/sqrt2)-1/(3sqrt2)tan^-1 (sqrt2 x)+c`

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

APPEARS IN

RELATED QUESTIONS

Find: `I=intdx/(sinx+sin2x)`


Evaluate: `∫8/((x+2)(x^2+4))dx` 


Integrate the rational function:

`x/((x -1)^2 (x+ 2))`


Integrate the rational function:

`1/(x^4 - 1)`


Find `int (2cos x)/((1-sinx)(1+sin^2 x)) dx`


Integrate the following w.r.t. x : `x^2/((x^2 + 1)(x^2 - 2)(x^2 + 3))`


Integrate the following w.r.t. x : `(3x - 2)/((x + 1)^2(x + 3)`


Integrate the following w.r.t. x : `(1)/(x(1 + 4x^3 + 3x^6)`


Integrate the following w.r.t. x: `(1)/(sinx + sin2x)`


Integrate the following w.r.t. x : `(5*e^x)/((e^x + 1)(e^(2x) + 9)`


Integrate the following with respect to the respective variable : `cot^-1 ((1 + sinx)/cosx)`


Integrate the following w.r.t.x : `x^2/sqrt(1 - x^6)`


Integrate the following w.r.t.x:

`x^2/((x - 1)(3x - 1)(3x - 2)`


Evaluate: `int (2"x" + 1)/(("x + 1")("x - 2"))` dx


`int "e"^(3logx) (x^4 + 1)^(-1) "d"x`


`int 1/(x(x^3 - 1)) "d"x`


`int sqrt((9 + x)/(9 - x))  "d"x`


`int sec^3x  "d"x`


`int sin(logx)  "d"x`


`int "e"^x ((1 + x^2))/(1 + x)^2  "d"x`


`int (x^2 + x -1)/(x^2 + x - 6)  "d"x`


`int ("d"x)/(2 + 3tanx)`


`int x^3tan^(-1)x  "d"x`


`int xcos^3x  "d"x`


`int  ((2logx + 3))/(x(3logx + 2)[(logx)^2 + 1])  "d"x`


Evaluate `int x log x  "d"x`


If `int(sin2x)/(sin5x  sin3x)dx = 1/3log|sin 3x| - 1/5log|f(x)| + c`, then f(x) = ______


Evaluate the following:

`int (x^2"d"x)/(x^4 - x^2 - 12)`


Evaluate the following:

`int (x^2 "d"x)/((x^2 + "a"^2)(x^2 + "b"^2))`


Evaluate the following:

`int (2x - 1)/((x - 1)(x + 2)(x - 3)) "d"x`


If `int "dx"/((x + 2)(x^2 + 1)) = "a"log|1 + x^2| + "b" tan^-1x + 1/5 log|x + 2| + "C"`, then ______.


The numerator of a fraction is 4 less than its denominator. If the numerator is decreased by 2 and the denominator is increased by 1, the denominator becomes eight times the numerator. Find the fraction.


Evaluate: `int_-2^1 sqrt(5 - 4x - x^2)dx`


Find : `int (2x^2 + 3)/(x^2(x^2 + 9))dx; x ≠ 0`.


Evaluate:

`int(2x^3 - 1)/(x^4 + x)dx`


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×