English

Integrate the rational function: x(x-1)2(x+2)

Advertisements
Advertisements

Question

Integrate the rational function:

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

Sum
Advertisements

Solution

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

`= A/((x - 1)) = B/((x - 1)^2) + C/((x + 2))`

⇒ x = A(x - 1)(x + 2) + B(x + 2) + C(x - 1)2   ...(1)

Put x = 1 

1 = 3B

⇒ B = `1/3`

Put x = -2 

-2 = C (-2 - 1)2

⇒ C = `(-2)/9`

On comparing the coefficients of x2

A = `-C = 2/9`

Hence,  `int x/((x+ 1)^2(x - 2))` dx

`= int 2/ (9 (x - 1)) dx + int 1/ (3 (x - 1)^2) dx - int 2/ (9(x + 2)) dx`

`= 2/9  log abs (x - 1) + 1/3 int (x - 1)^-1/-1 - 2/9  log abs (x + 2) + C`

`= 2/9  log abs ((x - 1)/(x + 2)) - 1/(3(x + 1)) + C`

shaalaa.com
  Is there an error in this question or solution?
Chapter 7: Integrals - Exercise 7.5 [Page 322]

APPEARS IN

NCERT Mathematics Part 1 and 2 [English] Class 12
Chapter 7 Integrals
Exercise 7.5 | Q 8 | Page 322

RELATED QUESTIONS

Integrate the rational function:

`(3x + 5)/(x^3 - x^2 - x + 1)`


Integrate the rational function:

`1/(x(x^n + 1))` [Hint: multiply numerator and denominator by xn − 1 and put xn = t]


Integrate the rational function:

`1/(e^x -1)`[Hint: Put ex = t]


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


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


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


Integrate the following w.r.t. x: `(2x^2 - 1)/(x^4 + 9x^2 + 20)`


Integrate the following with respect to the respective variable : `(cos 7x - cos8x)/(1 + 2 cos 5x)`


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)`


Evaluate: `int "3x - 2"/(("x + 1")^2("x + 3"))` dx


Evaluate: `int 1/("x"("x"^5 + 1))` dx


`int "dx"/(("x" - 8)("x" + 7))`=


Evaluate: `int ("3x" - 1)/("2x"^2 - "x" - 1)` dx


Evaluate: `int (2"x"^3 - 3"x"^2 - 9"x" + 1)/("2x"^2 - "x" - 10)` dx


Evaluate: `int (1 + log "x")/("x"(3 + log "x")(2 + 3 log "x"))` dx


`int x^7/(1 + x^4)^2  "d"x`


`int x^2sqrt("a"^2 - x^6)  "d"x`


`int (7 + 4x + 5x^2)/(2x + 3)^(3/2) dx`


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


Evaluate:

`int (5e^x)/((e^x + 1)(e^(2x) + 9)) dx`


`int (sin2x)/(3sin^4x - 4sin^2x + 1)  "d"x`


Choose the correct alternative:

`int (x + 2)/(2x^2 + 6x + 5) "d"x = "p"int (4x + 6)/(2x^2 + 6x + 5) "d"x + 1/2 int 1/(2x^2 + 6x + 5)"d"x`, then p = ?


`int (5(x^6 + 1))/(x^2 + 1) "d"x` = x5 – ______ x3 + 5x + c


If f'(x) = `1/x + x` and f(1) = `5/2`, then f(x) = log x + `x^2/2` + ______ + c


Evaluate `int x log x  "d"x`


If `intsqrt((x - 7)/(x - 9)) dx = Asqrt(x^2 - 16x + 63) + log|x - 8 + sqrt(x^2 - 16x + 63)| + c`, then A = ______


Evaluate the following:

`int x^2/(1 - x^4) "d"x` put x2 = t


Evaluate the following:

`int "e"^(-3x) cos^3x  "d"x`


Evaluate: `int (dx)/(2 + cos x - sin x)`


If f(x) = `int(3x - 1)x(x + 1)(18x^11 + 15x^10 - 10x^9)^(1/6)dx`, where f(0) = 0, is in the form of `((18x^α + 15x^β - 10x^γ)^δ)/θ`, then (3α + 4β + 5γ + 6δ + 7θ) is ______. (Where δ is a rational number in its simplest form)


If `int dx/sqrt(16 - 9x^2)` = A sin–1 (Bx) + C then A + B = ______.


Evaluate`int(5x^2-6x+3)/(2x-3)dx`


Evaluate: 

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


Evaluate.

`int (5x^2 - 6x + 3) / (2x -3) dx`


Evaluate:

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


Value of ∫ `(x^2 + 1)/((x − 1)(x − 2))`dx is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×