English

∫sin(logx) dx

Advertisements
Advertisements

Question

`int sin(logx)  "d"x`

Sum
Advertisements

Solution

Let I = `int sin(log x)  "d"x`

Put log x = t

∴ x = et

∴ dx = et dt 

∴ I = `int sin "t" * "e"^"t" "dt"`

= `sin "t" int "e"^"t" "dt" - int ["d"/"dt" (sin "t") int "e"^"t" "dt"]"dt"`

= `sin "t"* "e"^"t" - int cos "t" * "e"^"t" "dt"`

= `"e"^"t" sin "t" - [cos "t" int "e"^"t" "dt" - int ("d"/"dt"(cos "t") int "e"^"t" "dt")"dt"]`

= `"e"^"t" sin "t" - ["e"^"t" cos "t" - int(- sin "t")"e"^"t" "dt"]`

= `"e"^"t" sin "t" - "e"^"t"cos "t" - int sin "t" * "e"^"t" "dt"`

∴ I = `"e"^"t"(sin "t"- cos "t") - "I" + "c"_1`

∴ 2I = `"e"^"t"(sin "t" - cos "t") + "c"_1`

∴ I = `"e"^"t"/2 (sin "t" - cos "t") + "c"_1/2`

∴ I = `x/2 [sin (log x) - cos(log x)] + "c"`, 

where c = `"c"_1/2`

shaalaa.com
  Is there an error in this question or solution?
Chapter 2.3: Indefinite Integration - Short Answers II

RELATED QUESTIONS

Evaluate:

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


Integrate the rational function:

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


Integrate the rational function:

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


Integrate the rational function:

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


Integrate the rational function:

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


Integrate the rational function:

`((x^2 +1)(x^2 + 2))/((x^2 + 3)(x^2+ 4))`


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


Evaluate : `∫(x+1)/((x+2)(x+3))dx`


Integrate the following w.r.t. x : `(12x + 3)/(6x^2 + 13x - 63)`


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


Integrate the following w.r.t. x : `(1)/(x(x^5 + 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)/(sin2x + cosx)`


Integrate the following w.r.t. x : `(1)/(sinx*(3 + 2cosx)`


Integrate the following w.r.t. x : `(2log x + 3)/(x(3 log x + 2)[(logx)^2 + 1]`


Integrate the following with respect to the respective variable : `(6x + 5)^(3/2)`


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 : `(1)/((1 - cos4x)(3 - cot2x)`


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


Integrate the following w.r.t.x :  `sec^2x sqrt(7 + 2 tan x - tan^2 x)`


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


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


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


`int sec^3x  "d"x`


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


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


`int x sin2x cos5x  "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 1/x^3 [log x^x]^2  "d"x` = p(log x)3 + c Then p = ______


Evaluate `int x^2"e"^(4x)  "d"x`


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


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


Verify the following using the concept of integration as an antiderivative

`int (x^3"d"x)/(x + 1) = x - x^2/2 + x^3/3 - log|x + 1| + "C"`


Evaluate the following:

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


Evaluate the following:

`int "e"^(-3x) cos^3x  "d"x`


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


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


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


Evaluate:

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


If \[\int\frac{2x+3}{(x-1)(x^{2}+1)}\mathrm{d}x\] = \[=\log_{e}\left\{(x-1)^{\frac{5}{2}}\left(x^{2}+1\right)^{a}\right\}-\frac{1}{2}\tan^{-1}x+\mathrm{A}\] where A is an arbitrary constant, then the value of a is


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×