हिंदी

Evaluate π∫0π/4log(1+tanx)dx.

Advertisements
Advertisements

प्रश्न

Evaluate `int_0^(π//4) log (1 + tanx)dx`.

योग
Advertisements

उत्तर

Let I = `int_0^(π//4) log (1 + tanx)dx`  ...(i)

By using property

`int_0^a f(x) = int_0^a f(a - x)`

I = `int_0^(π//4) log [1 + tan(π/4 - x)]dx`

= `int_0^(π//4) log [1 + (tan  π/4 - tan x)/(1 + tan  π/4 tan x)]dx`

= `int_0^(π//4) log [1 + (1 - tanx)/(1 + tanx)]dx`

= `int_0^(π//4) log [2/(1 + tanx)]dx`

= `int_0^(π//4) log 2 - int_0^(π//4) log (1 + tanx)dx`  ...(ii)

On adding equations (i) and (ii),

2I = `int_0^(π//4) log (1 + tanx)dx + int_0^(π//4) log 2 dx - int_0^(π//4) log (1 + tanx)dx`

`\implies` 2I = `int_0^(π//4) log 2 dx` 

`\implies` 2I = `log 2 int_0^(π//4) 1.dx`

`\implies` 2I = `log 2 [x]_0^(π//4)`

`\implies` I = `log2/2 xx π/4 = π/8 log 2`

shaalaa.com
  क्या इस प्रश्न या उत्तर में कोई त्रुटि है?
2022-2023 (March) Outside Delhi Set 1

संबंधित प्रश्न

Prove that: `int_0^(2a)f(x)dx=int_0^af(x)dx+int_0^af(2a-x)dx`


By using the properties of the definite integral, evaluate the integral:

`int_0^(pi/2) cos^2 x dx`


By using the properties of the definite integral, evaluate the integral:

`int_(-5)^5 | x + 2| dx`


By using the properties of the definite integral, evaluate the integral:

`int_0^(pi/2) (2log sin x - log sin 2x)dx`


By using the properties of the definite integral, evaluate the integral:

`int_0^pi (x  dx)/(1+ sin x)`


Prove that `int_0^"a" "f" ("x") "dx" = int_0^"a" "f" ("a" - "x") "d x",` hence evaluate `int_0^pi ("x" sin "x")/(1 + cos^2 "x") "dx"`


Evaluate: `int_0^pi ("x"sin "x")/(1+ 3cos^2 "x") d"x"`.


Find : `int_  (2"x"+1)/(("x"^2+1)("x"^2+4))d"x"`.


State whether the following statement is True or False:

`int_(-5)^5 x/(x^2 + 7)  "d"x` = 10


`int_0^{pi/2} log(tanx)dx` = ______


`int_0^4 1/(1 + sqrtx)`dx = ______.


`int_"a"^"b" sqrtx/(sqrtx + sqrt("a" + "b" - x)) "dx"` = ______.


If `int_0^"k" "dx"/(2 + 32x^2) = pi/32,` then the value of k is ______.


`int_0^{pi/2} (cos2x)/(cosx + sinx)dx` = ______


`int_(-1)^1 (x + x^3)/(9 - x^2)  "d"x` = ______.


If `int_0^1 "e"^"t"/(1 + "t") "dt"` = a, then `int_0^1 "e"^"t"/(1 + "t")^2 "dt"` is equal to ______.


Evaluate:

`int_2^8 (sqrt(10 - "x"))/(sqrt"x" + sqrt(10 - "x")) "dx"`


Evaluate: `int_0^(π/2) 1/(1 + (tanx)^(2/3)) dx`


Evaluate: `int_0^(2π) (1)/(1 + e^(sin x)`dx


Evaluate: `int_((-π)/2)^(π/2) (sin|x| + cos|x|)dx`


`int_0^1|3x - 1|dx` equals ______.


Let `int ((x^6 - 4)dx)/((x^6 + 2)^(1/4).x^4) = (ℓ(x^6 + 2)^m)/x^n + C`, then `n/(ℓm)` is equal to ______.


Let f be continuous periodic function with period 3, such that `int_0^3f(x)dx` = 1. Then the value of `int_-4^8f(2x)dx` is ______.


`int_(π/3)^(π/2) x sin(π[x] - x)dx` is equal to ______.


If `int_0^K dx/(2 + 18x^2) = π/24`, then the value of K is ______.


Evaluate the following integral:

`int_0^1 x(1 - 5)^5`dx


`int_1^2 x logx  dx`= ______


Evaluate the following integral:

`int_0^1x(1-x)^5dx`


Evaluate the following integral:

`int_-9^9x^3/(4-x^2)dx`


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×