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sqrt(1-r^2)*r

Integral of sqrt(1-r^2)*r dr

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The solution

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01r1r2dr\int\limits_{0}^{1} r \sqrt{1 - r^{2}}\, dr
Integral(sqrt(1 - r^2)*r, (r, 0, 1))
Detail solution
  1. Let u=1r2u = 1 - r^{2}.

    Then let du=2rdrdu = - 2 r dr and substitute du2- \frac{du}{2}:

    (u2)du\int \left(- \frac{\sqrt{u}}{2}\right)\, du

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

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

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

        udu=2u323\int \sqrt{u}\, du = \frac{2 u^{\frac{3}{2}}}{3}

      So, the result is: u323- \frac{u^{\frac{3}{2}}}{3}

    Now substitute uu back in:

    (1r2)323- \frac{\left(1 - r^{2}\right)^{\frac{3}{2}}}{3}

  2. Add the constant of integration:

    (1r2)323+constant- \frac{\left(1 - r^{2}\right)^{\frac{3}{2}}}{3}+ \mathrm{constant}


The answer is:

(1r2)323+constant- \frac{\left(1 - r^{2}\right)^{\frac{3}{2}}}{3}+ \mathrm{constant}

The answer (Indefinite) [src]
  /                                  
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r1r2dr=C(1r2)323\int r \sqrt{1 - r^{2}}\, dr = C - \frac{\left(1 - r^{2}\right)^{\frac{3}{2}}}{3}
The graph
0.001.000.100.200.300.400.500.600.700.800.901.0-1.0
The answer [src]
1/3
13\frac{1}{3}
=
=
1/3
13\frac{1}{3}
1/3
Numerical answer [src]
0.333333333333333
0.333333333333333
The graph
Integral of sqrt(1-r^2)*r dr

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