English

Evaluate: ∫dx2+cosx-sinx - Mathematics and Statistics

Advertisements
Advertisements

Question

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

Sum
Advertisements

Solution

Let I = `int (dx)/(2 + cos x - sin x)`

Put `tan  x/2` = t

⇒ x = 2 tan–1t

∴ dx = `(2 dt)/(1 + t^2)`

And sin x = `(2t)/(1 + t^2)`, cos x = `(1 - t^2)/(1 + t^2)`

∴ I = `int 1/(2 + ((1  -  t^2)/(1  +  t^2)) - ((2t)/(1 + t^2))) * (2dt)/(1  +  t^2)`

= `int (1 + t^2)/(2 + 2t^2 + 1 - t^2 - 2t) * (2dt)/(1 + t^2)`

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

= `2int 1/((t - 1)^2 + (sqrt(2))^2)  dt`

= `2 xx 1/sqrt(2)  tan^-1  ((t - 1)/sqrt(2)) + C`

= `sqrt(2)tan^-1 ((tan(x/2) - 1)/sqrt(2)) + C`

shaalaa.com
  Is there an error in this question or solution?
2021-2022 (March) Set 1

RELATED QUESTIONS

Integrate the rational function:

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


Integrate the rational function:

`(5x)/((x + 1)(x^2 - 4))`


Integrate the rational function:

`1/(x(x^4 - 1))`


Integrate the following w.r.t. x : `(2x)/(4 - 3x - x^2)`


Integrate the following w.r.t. x:

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


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


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)/(x^3 - 1)`


Integrate the following w.r.t. x : `((3sin - 2)*cosx)/(5 - 4sin x - cos^2x)`


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


Integrate the following w.r.t. x : `(1)/(2sinx + sin2x)`


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


Integrate the following w.r.t.x : `sqrt(tanx)/(sinx*cosx)`


Evaluate: `int ("x"^2 + "x" - 1)/("x"^2 + "x" - 6)` dx


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


Evaluate: `int (5"x"^2 + 20"x" + 6)/("x"^3 + 2"x"^2 + "x")` dx


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


`int x^2sqrt("a"^2 - x^6)  "d"x`


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


`int (sinx)/(sin3x)  "d"x`


`int 1/(2 +  cosx - sinx)  "d"x`


`int sin(logx)  "d"x`


`int sec^2x sqrt(tan^2x + tanx - 7)  "d"x`


`int "e"^(sin^(-1_x))[(x + sqrt(1 - x^2))/sqrt(1 - x^2)] "d"x`


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


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


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


`int (x + sinx)/(1 - cosx)  "d"x`


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


Evaluate:

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


`int 1/(sinx(3 + 2cosx))  "d"x`


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


`int (3"e"^(2x) + 5)/(4"e"^(2x) - 5)  "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


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


`int 1/(4x^2 - 20x + 17)  "d"x`


Evaluate the following:

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


Evaluate the following:

`int sqrt(tanx)  "d"x`  (Hint: Put tanx = t2)


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


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 ______.


If `intsqrt((x - 5)/(x - 7))dx = Asqrt(x^2 - 12x + 35) + log|x| - 6 + sqrt(x^2 - 12x + 35) + C|`, then A = ______.


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


Evaluate:

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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×