English

∫cos7x dx - Mathematics and Statistics

Advertisements
Advertisements

Question

`int cos^7 x  "d"x`

Sum

Solution

Let I = `int cos^7 x  "d"x`

= `int(cos^2x)^3*cosx  "d"x`

= `int (1 - sin^2x)^3* cosx  "d"x`

Put sin x = t

∴ cos x dx = dt

∴ I = `int (1 - "t"^2)^3 "dt"`

= `int (1 - 3"t"^2 + 3"t"^4 - "t"^6) "dt"`

= `int 1* "dt" - 3 int "t"^2  "dt" + 3 int "t"^4 "dt" - int "t"^6 "dt"`

= `"t" - 3 ("t"^3/3) + 3"t"^5/5) - "t"^7/7 + "c"`

∴ I = `sinx - sin^3x + 3/5 sin^5x - 1/7 sin^7x + "c"`

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

RELATED QUESTIONS

Evaluate : `int_0^pi(x)/(a^2cos^2x+b^2sin^2x)dx`


Evaluate :`intxlogxdx`


Evaluate :

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


Find `int((3sintheta-2)costheta)/(5-cos^2theta-4sin theta)d theta`


Integrate the functions:

sin x ⋅ sin (cos x)


Integrate the functions:

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


Integrate the functions:

`1/(1 + cot x)`


Integrate the functions:

`1/(1 - tan x)`


Integrate the functions:

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


Evaluate: `int 1/(x(x-1)) dx`


\[\int\sqrt{1 + x - 2 x^2} \text{ dx }\]

Write a value of

\[\int\frac{\cos x}{3 + 2 \sin x}\text{  dx}\]

Write a value of

\[\int e^{\text{ log  sin x  }}\text{ cos x}. \text{ dx}\]

Write a value of\[\int \cos^4 x \text{ sin x dx }\]


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


Write a value of\[\int e^{ax} \sin\ bx\ dx\]


Write a value of\[\int e^x \left( \frac{1}{x} - \frac{1}{x^2} \right) dx\] .


Write a value of\[\int e^{ax} \left\{ a f\left( x \right) + f'\left( x \right) \right\} dx\] .


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


Evaluate:  \[\int\frac{x^3 - 1}{x^2} \text{ dx}\]


Evaluate : `int ("e"^"x" (1 + "x"))/("cos"^2("x""e"^"x"))"dx"`


 Prove that: `int "dx"/(sqrt("x"^2 +"a"^2)) = log  |"x" +sqrt("x"^2 +"a"^2) | + "c"`


Integrate the following w.r.t. x:

`3 sec^2x - 4/x + 1/(xsqrt(x)) - 7`


Integrate the following w.r.t. x:

`2x^3 - 5x + 3/x + 4/x^5`


Evaluate the following integrals : tan2x dx


Evaluate the following integrals : `int (sin2x)/(cosx)dx`


Evaluate the following integrals : `int sqrt(1 + sin 2x) dx`


Evaluate the following integrals : `intsqrt(1 - cos 2x)dx`


Integrate the following functions w.r.t. x : `(logx)^n/x`


Integrate the following functions w.r.t. x : `e^(3x)/(e^(3x) + 1)`


Integrate the following functions w.r.t. x : `e^x.log (sin e^x)/tan(e^x)`


Integrate the following functions w.r.t. x : `(1)/(sqrt(x) + sqrt(x^3)`


Integrate the following functions w.r.t. x : `sin(x - a)/cos(x  + b)`


Integrate the following functions w.r.t. x : cos7x


Evaluate the following : `int sqrt((10 + x)/(10 - x)).dx`


Evaluate the following : `int  (1)/(x^2 + 8x + 12).dx`


Evaluate the following : `int (1)/(5 - 4x - 3x^2).dx`


Evaluate the following : `int (1)/(cos2x + 3sin^2x).dx`


Integrate the following functions w.r.t. x : `int (1)/(3 + 2sin x - cosx)dx`


Integrate the following functions w.r.t. x : `int (1)/(3 + 2 sin2x + 4cos 2x).dx`


Integrate the following functions w.r.t. x : `int (1)/(cosx - sinx).dx`


Evaluate the following integrals:

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


Evaluate the following integrals :  `int (3x + 4)/sqrt(2x^2 + 2x + 1).dx`


Choose the correct options from the given alternatives :

`int sqrt(cotx)/(sinx*cosx)*dx` =


Choose the correct options from the given alternatives :

`2 int (cos^2x - sin^2x)/(cos^2x + sin^2x)*dx` =


Evaluate `int 1/("x" ("x" - 1))` dx


If f'(x) = x2 + 5 and f(0) = −1, then find the value of f(x).


Evaluate the following.

`int 1/("x" log "x")`dx


Evaluate the following.

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


Evaluate the following.

`int 1/(4"x"^2 - 20"x" + 17)` dx


Fill in the Blank.

`int (5("x"^6 + 1))/("x"^2 + 1)` dx = x4 + ______ x3 + 5x + c


`int (x^2 + x - 6)/((x - 2)(x - 1))dx = x` + ______ + c


Fill in the Blank.

To find the value of `int ((1 + log "x") "dx")/"x"` the proper substitution is ________


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 "x - 1"/sqrt("x + 4")` dx


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


Evaluate: `int "x" * "e"^"2x"` dx


`int 1/sqrt((x - 3)(x + 2))` dx = ______.


`int "e"^x[((x + 3))/((x + 4)^2)] "d"x`


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


`int (7x + 9)^13  "d"x` ______ + c


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


If f(x) = 3x + 6, g(x) = 4x + k and fog (x) = gof (x) then k = ______.


If `tan^-1x = 2tan^-1((1 - x)/(1 + x))`, then the value of x is ______ 


`int ((x + 1)(x + log x))^4/(3x) "dx" =`______.


`int ("d"x)/(sinx cosx + 2cos^2x)` = ______.


If f'(x) = `x + 1/x`, then f(x) is ______.


`int (f^'(x))/(f(x))dx` = ______ + c.


`int x/sqrt(1 - 2x^4) dx` = ______.

(where c is a constant of integration)


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


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


Find `int (x + 2)/sqrt(x^2 - 4x - 5) dx`.


`int secx/(secx - tanx)dx` equals ______.


Find : `int sqrt(x/(1 - x^3))dx; x ∈ (0, 1)`.


Evaluated the following

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


Evaluate `int (1+x+x^2/(2!))dx`


Evaluate the following.

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


if `f(x) = 4x^3 - 3x^2 + 2x +k, f (0) = - 1 and f (1) = 4, "find " f(x)`


Evaluate the following

`int1/(x^2 +4x-5)dx`


Evaluate `int1/(x(x - 1))dx`


Evaluate the following.

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


`int 1/(sin^2x cos^2x)dx` = ______.


Evaluate the following.

`intx sqrt(1 +x^2)  dx`


Evaluate:

`int(cos 2x)/sinx dx`


`int (cos4x)/(sin2x + cos2x)dx` = ______.


The value of `int ("d"x)/(sqrt(1 - x))` is ______.


Evaluate the following:

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


Evaluate `int 1/(x(x-1))dx`


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


Evaluate:

`intsqrt(sec  x/2 - 1)dx`


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×