English

Integrate the following functions w.r.t.x: cos8xcotx

Advertisements
Advertisements

Question

Integrate the following functions w.r.t.x:

cos8xcotx

Sum
Advertisements

Solution

Let I = `int cos^8xcotxdx`

= `int cos^8x. cosx/sinx .dx`

Put sinx = t

∴ cosx dx = dt

cos8x = (cos2x)4

= (1 – sin2x)4

= (1 – t2)4

= 1 –  4t2 + 6t4 – 4t6 + t8

I = `int(1 - 4t^2 + 6t^4 - 4t^6 + t^8)/tdt`

= `int[1/t - 4t +6t^3 - 4t^5 + t^7]dt`

= `int 1/t dx - 4 int tdt + 6 int t^3 dt - 4 int t^5 dt + int t^7 dt`

= `log|t| - 4 (t^2/2) + 6(t^4/4) - 4(t^6/6) + t^8/(8) + c`

= `log|sinx| - 2sin^2x + 3/2 sin^4x - 2/3 sin^6x + (sin^8x)/(8) + c`.

shaalaa.com
  Is there an error in this question or solution?
Chapter 3: Indefinite Integration - Exercise 3.2 (A) [Page 110]

RELATED QUESTIONS

Evaluate : `int (sinx)/sqrt(36-cos^2x)dx`


Evaluate : `int(x-3)sqrt(x^2+3x-18)  dx`


Evaluate :

`int(sqrt(cotx)+sqrt(tanx))dx`


Integrate the functions:

`1/(x + x log x)`


Integrate the functions:

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


Integrate the functions:

`(2cosx - 3sinx)/(6cos x + 4 sin x)`


Integrate the functions:

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


Integrate the functions:

`cos sqrt(x)/sqrtx`


Integrate the functions:

`sin x/(1+ cos x)`


Integrate the functions:

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


\[\int\cos x \sqrt{4 - \sin^2 x}\text{ dx}\]

Write a value of

\[\int \tan^6 x \sec^2 x \text{ dx }\] .

Write a value of \[\int\frac{1 - \sin x}{\cos^2 x} \text{ dx }\]


The value of \[\int\frac{\cos \sqrt{x}}{\sqrt{x}} dx\] is


The value of \[\int\frac{1}{x + x \log x} dx\] is


Integrate the following w.r.t. x : x3 + x2 – x + 1


Integrate the following functions w.r.t. x : `(e^(2x) + 1)/(e^(2x) - 1)`


Integrate the following functions w.r.t.x:

`(5 - 3x)(2 - 3x)^(-1/2)`


Integrate the following functions w.r.t. x : `(20 + 12e^x)/(3e^x + 4)`


Integrate the following functions w.r.t. x : `3^(cos^2x) sin 2x`


Evaluate the following : `int (1)/sqrt(x^2 + 8x - 20).dx`


Choose the correct options from the given alternatives :

`int f x^x (1 + log x)*dx`


If f'(x) = 4x3 − 3x2  + 2x + k, f(0) = 1 and f(1) = 4, find f(x).


Evaluate the following.

`int ("2x" + 6)/(sqrt("x"^2 + 6"x" + 3))` dx


Evaluate the following.

`int 1/(x(x^6 + 1))` dx 


Evaluate the following.

`int "x"^3/(16"x"^8 - 25)` dx


Evaluate the following.

`int 1/(sqrt("x"^2 -8"x" - 20))` dx


State whether the following statement is True or False.

If ∫ x f(x) dx = `("f"("x"))/2`, then find f(x) = `"e"^("x"^2)`


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


Evaluate: `int "e"^sqrt"x"` dx


`int e^x/x [x (log x)^2 + 2 log x]` dx = ______________


`int cos sqrtx` dx = _____________


`int (sin4x)/(cos 2x) "d"x`


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


`int cot^2x  "d"x`


`int x/(x + 2)  "d"x`


`int (x^2 + 1)/(x^4 - x^2 + 1)`dx = ?


The integral `int ((1 - 1/sqrt(3))(cosx - sinx))/((1 + 2/sqrt(3) sin2x))dx` is equal to ______.


If `int [log(log x) + 1/(logx)^2]dx` = x [f(x) – g(x)] + C, then ______.


`int(1 - x)^(-2)` dx = `(1 - x)^(-1) + c`


Find `int dx/sqrt(sin^3x cos(x - α))`.


Evaluated the following

`int x^3/ sqrt (1 + x^4 )dx`


Evaluate the following.

`int 1/(x^2 + 4x - 5)  dx`


Prove that:

`int 1/sqrt(x^2 - a^2) dx = log |x + sqrt(x^2 - a^2)| + c`.


Evaluate:

`int sqrt((a - x)/x) dx`


If f ′(x) = 4x3 − 3x2 + 2x + k, f(0) = 1 and f(1) = 4, find f(x)


`int "cosec"^4x  dx` = ______.


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


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×