English

Evaluate: ππ∫-π/4π/4cos2x1+cos2xdx. - Mathematics

Advertisements
Advertisements

Question

Evaluate: `int_(-π//4)^(π//4) (cos 2x)/(1 + cos 2x)dx`.

Sum
Advertisements

Solution

`int_(-π//4)^(π//4) (cos 2x)/(1 + cos 2x)dx = int_(-π//4)^(π//4) (2 cos^2 x - 1)/(2 cos^2 x)dx`

= `1/2 . 2 int_0^(π//4) (2 - sec^2 x)dx`  ...[even function]

= `1/2 . 2[2x - tan x]_0^(π//4)`

= `π/2 - 1`

shaalaa.com
  Is there an error in this question or solution?
2022-2023 (March) Delhi Set 2

RELATED QUESTIONS

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


 
 

Evaluate `int_(-2)^2x^2/(1+5^x)dx`

 
 

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

`int_0^pi (x  dx)/(1+ sin x)`


Show that `int_0^a f(x)g (x)dx = 2 int_0^a f(x) dx`  if f and g are defined as f(x) = f(a-x) and g(x) + g(a-x) = 4.


The total revenue R = 720 - 3x2 where x is number of items sold. Find x for which total  revenue R is increasing.


Evaluate `int_1^2 (sqrt(x))/(sqrt(3 - x) + sqrt(x))  "d"x`


`int_0^(pi/4) (sec^2 x)/((1 + tan x)(2 + tan x))`dx = ?


`int_0^1 ((x^2 - 2)/(x^2 + 1))`dx = ?


`int_0^1 (1 - x)^5`dx = ______.


`int_0^pi x sin^2x dx` = ______ 


`int_(-pi/4)^(pi/4) 1/(1 - sinx) "d"x` = ______.


Show that `int_0^(pi/2) (sin^2x)/(sinx + cosx) = 1/sqrt(2) log (sqrt(2) + 1)`


Evaluate the following:

`int_0^(pi/2)  "dx"/(("a"^2 cos^2x + "b"^2 sin^2 x)^2` (Hint: Divide Numerator and Denominator by cos4x)


`int_(-5)^5  x^7/(x^4 + 10)  dx` = ______.


Evaluate: `int_1^3 sqrt(x)/(sqrt(x) + sqrt(4) - x) dx`


Evaluate: `int_(-1)^3 |x^3 - x|dx`


If `int_a^b x^3 dx` = 0, then `(x^4/square)_a^b` = 0

⇒ `1/4 (square - square)` = 0

⇒ b4 – `square` = 0

⇒ (b2 – a2)(`square` + `square`) = 0

⇒ b2 – `square` = 0 as a2 + b2 ≠ 0

⇒ b = ± `square`


If `int_(-a)^a(|x| + |x - 2|)dx` = 22, (a > 2) and [x] denotes the greatest integer ≤ x, then `int_a^(-a)(x + [x])dx` is equal to ______.


Let a be a positive real number such that `int_0^ae^(x-[x])dx` = 10e – 9 where [x] is the greatest integer less than or equal to x. Then, a is equal to ______.


`int_0^π(xsinx)/(1 + cos^2x)dx` equals ______.


The value of the integral `int_0^sqrt(2)([sqrt(2 - x^2)] + 2x)dx` (where [.] denotes greatest integer function) is ______.


Let `int_0^∞ (t^4dt)/(1 + t^2)^6 = (3π)/(64k)` then k is equal to ______.


If f(x) = `{{:(x^2",", "where"  0 ≤ x < 1),(sqrt(x)",", "when"  1 ≤ x < 2):}`, then `int_0^2f(x)dx` equals ______.


`int_-1^1 (17x^5 - x^4 + 29x^3 - 31x + 1)/(x^2 + 1) dx` is equal to ______.


If `int_0^(2π) cos^2 x  dx = k int_0^(π/2) cos^2 x  dx`, then the value of k is ______.


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


Solve the following.

`int_1^3 x^2 logx  dx`


Evaluate the following integral:

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


Evaluate the following integral:

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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×