Mister Exam

Integral of arcsin2x dx

Limits of integration:

from to
v

The graph:

from to

Piecewise:

The solution

You have entered [src]
 1/4            
  /             
 |              
 |  asin(2*x) dx
 |              
/               
0               
014asin(2x)dx\int\limits_{0}^{\frac{1}{4}} \operatorname{asin}{\left(2 x \right)}\, dx
Integral(asin(2*x), (x, 0, 1/4))
Detail solution
  1. There are multiple ways to do this integral.

    Method #1

    1. Let u=2xu = 2 x.

      Then let du=2dxdu = 2 dx and substitute du2\frac{du}{2}:

      asin(u)2du\int \frac{\operatorname{asin}{\left(u \right)}}{2}\, du

      1. The integral of a constant times a function is the constant times the integral of the function:

        asin(u)du=asin(u)du2\int \operatorname{asin}{\left(u \right)}\, du = \frac{\int \operatorname{asin}{\left(u \right)}\, du}{2}

        1. Use integration by parts:

          udv=uvvdu\int \operatorname{u} \operatorname{dv} = \operatorname{u}\operatorname{v} - \int \operatorname{v} \operatorname{du}

          Let u(u)=asin(u)u{\left(u \right)} = \operatorname{asin}{\left(u \right)} and let dv(u)=1\operatorname{dv}{\left(u \right)} = 1.

          Then du(u)=11u2\operatorname{du}{\left(u \right)} = \frac{1}{\sqrt{1 - u^{2}}}.

          To find v(u)v{\left(u \right)}:

          1. The integral of a constant is the constant times the variable of integration:

            1du=u\int 1\, du = u

          Now evaluate the sub-integral.

        2. Let u=1u2u = 1 - u^{2}.

          Then let du=2ududu = - 2 u du and substitute du2- \frac{du}{2}:

          (12u)du\int \left(- \frac{1}{2 \sqrt{u}}\right)\, du

          1. The integral of a constant times a function is the constant times the integral of the function:

            1udu=1udu2\int \frac{1}{\sqrt{u}}\, du = - \frac{\int \frac{1}{\sqrt{u}}\, du}{2}

            1. The integral of unu^{n} is un+1n+1\frac{u^{n + 1}}{n + 1} when n1n \neq -1:

              1udu=2u\int \frac{1}{\sqrt{u}}\, du = 2 \sqrt{u}

            So, the result is: u- \sqrt{u}

          Now substitute uu back in:

          1u2- \sqrt{1 - u^{2}}

        So, the result is: uasin(u)2+1u22\frac{u \operatorname{asin}{\left(u \right)}}{2} + \frac{\sqrt{1 - u^{2}}}{2}

      Now substitute uu back in:

      xasin(2x)+14x22x \operatorname{asin}{\left(2 x \right)} + \frac{\sqrt{1 - 4 x^{2}}}{2}

    Method #2

    1. Use integration by parts:

      udv=uvvdu\int \operatorname{u} \operatorname{dv} = \operatorname{u}\operatorname{v} - \int \operatorname{v} \operatorname{du}

      Let u(x)=asin(2x)u{\left(x \right)} = \operatorname{asin}{\left(2 x \right)} and let dv(x)=1\operatorname{dv}{\left(x \right)} = 1.

      Then du(x)=214x2\operatorname{du}{\left(x \right)} = \frac{2}{\sqrt{1 - 4 x^{2}}}.

      To find v(x)v{\left(x \right)}:

      1. The integral of a constant is the constant times the variable of integration:

        1dx=x\int 1\, dx = x

      Now evaluate the sub-integral.

    2. The integral of a constant times a function is the constant times the integral of the function:

      2x14x2dx=2x14x2dx\int \frac{2 x}{\sqrt{1 - 4 x^{2}}}\, dx = 2 \int \frac{x}{\sqrt{1 - 4 x^{2}}}\, dx

      1. Let u=14x2u = 1 - 4 x^{2}.

        Then let du=8xdxdu = - 8 x dx and substitute du8- \frac{du}{8}:

        (18u)du\int \left(- \frac{1}{8 \sqrt{u}}\right)\, du

        1. The integral of a constant times a function is the constant times the integral of the function:

          1udu=1udu8\int \frac{1}{\sqrt{u}}\, du = - \frac{\int \frac{1}{\sqrt{u}}\, du}{8}

          1. The integral of unu^{n} is un+1n+1\frac{u^{n + 1}}{n + 1} when n1n \neq -1:

            1udu=2u\int \frac{1}{\sqrt{u}}\, du = 2 \sqrt{u}

          So, the result is: u4- \frac{\sqrt{u}}{4}

        Now substitute uu back in:

        14x24- \frac{\sqrt{1 - 4 x^{2}}}{4}

      So, the result is: 14x22- \frac{\sqrt{1 - 4 x^{2}}}{2}

  2. Add the constant of integration:

    xasin(2x)+14x22+constantx \operatorname{asin}{\left(2 x \right)} + \frac{\sqrt{1 - 4 x^{2}}}{2}+ \mathrm{constant}


The answer is:

xasin(2x)+14x22+constantx \operatorname{asin}{\left(2 x \right)} + \frac{\sqrt{1 - 4 x^{2}}}{2}+ \mathrm{constant}

The answer (Indefinite) [src]
                         __________              
  /                     /        2               
 |                    \/  1 - 4*x                
 | asin(2*x) dx = C + ------------- + x*asin(2*x)
 |                          2                    
/                                                
asin(2x)dx=C+xasin(2x)+14x22\int \operatorname{asin}{\left(2 x \right)}\, dx = C + x \operatorname{asin}{\left(2 x \right)} + \frac{\sqrt{1 - 4 x^{2}}}{2}
The graph
0.0000.2500.0250.0500.0750.1000.1250.1500.1750.2000.2250.01.0
The answer [src]
        ___     
  1   \/ 3    pi
- - + ----- + --
  2     4     24
12+π24+34- \frac{1}{2} + \frac{\pi}{24} + \frac{\sqrt{3}}{4}
=
=
        ___     
  1   \/ 3    pi
- - + ----- + --
  2     4     24
12+π24+34- \frac{1}{2} + \frac{\pi}{24} + \frac{\sqrt{3}}{4}
-1/2 + sqrt(3)/4 + pi/24
Numerical answer [src]
0.063912395791794
0.063912395791794

    Use the examples entering the upper and lower limits of integration.