English

Integrate the rational function: 1x2-9 - Mathematics

Advertisements
Advertisements

Question

Integrate the rational function:

`1/(x^2 - 9)`

Sum
Advertisements

Solution

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

`= A/(x - 3) + B/(x + 3)`

⇒ 1 ≡ A(x + 3) + B(x - 3)

Put x = 3

1 = A (3 + 3)

⇒ A `= 1/6`

again, put x = -3

1 = B(3 - 3)

⇒ B `= -1/6`

`therefore 1/(x^2 - 9) = 1/6 [1/(x - 3) - 1/(x + 3)]`

`=> int 1/(x^2 - 9) = 1/6 int (1/(x - 3) - 1/(x + 3))` dx

`= 1/6 [log  abs (x - 3) - log  abs (x + 3)] + C`

`= 1/6  log abs ((x - 3)/(x + 3)) + 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 2 | Page 322

RELATED QUESTIONS

Find : `int x^2/(x^4+x^2-2) dx`


Integrate the rational function:

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


Integrate the rational function:

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


Integrate the rational function:

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


Integrate the rational function:

`(cos x)/((1-sinx)(2 - sin x))` [Hint: Put sin x = t]


Integrate the rational function:

`1/(e^x -1)`[Hint: Put ex = t]


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


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 : `(12x + 3)/(6x^2 + 13x - 63)`


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


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


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


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


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


Integrate the following w.r.t.x: `(x + 5)/(x^3 + 3x^2 - x - 3)`


Evaluate:

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


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


`int (2x - 7)/sqrt(4x- 1) dx`


`int ((x^2 + 2))/(x^2 + 1) "a"^(x + tan^(-1_x)) "d"x`


`int sqrt((9 + x)/(9 - x))  "d"x`


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


`int (6x^3 + 5x^2 - 7)/(3x^2 - 2x - 1)  "d"x`


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


`int xcos^3x  "d"x`


Choose the correct alternative:

`int sqrt(1 + x)  "d"x` =


Evaluate `int x^2"e"^(4x)  "d"x`


`int 1/(4x^2 - 20x + 17)  "d"x`


Evaluate the following:

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


Evaluate the following:

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


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)


Let g : (0, ∞) `rightarrow` R be a differentiable function such that `int((x(cosx - sinx))/(e^x + 1) + (g(x)(e^x + 1 - xe^x))/(e^x + 1)^2)dx = (xg(x))/(e^x + 1) + c`, for all x > 0, where c is an arbitrary constant. Then ______.


Find: `int x^4/((x - 1)(x^2 + 1))dx`.


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


Evaluate:

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


Evaluate.

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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×