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x^2*e^(-x)*dx

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x^2*e^(-x)*dx

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Integral of x^2*e^(-x)*dx dx

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The solution

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  1            
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01x2ex1dx\int\limits_{0}^{1} x^{2} e^{- x} 1\, dx
Integral(x^2*1/E^(1*x), (x, 0, 1))
Detail solution
  1. Use integration by parts:

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

    Let u(x)=x2u{\left(x \right)} = x^{2} and let dv(x)=ex\operatorname{dv}{\left(x \right)} = e^{- x}.

    Then du(x)=2x\operatorname{du}{\left(x \right)} = 2 x.

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

    1. There are multiple ways to do this integral.

      Method #1

      1. Let u=xu = - x.

        Then let du=dxdu = - dx and substitute du- du:

        eudu\int e^{u}\, du

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

          (eu)du=eudu\int \left(- e^{u}\right)\, du = - \int e^{u}\, du

          1. The integral of the exponential function is itself.

            eudu=eu\int e^{u}\, du = e^{u}

          So, the result is: eu- e^{u}

        Now substitute uu back in:

        ex- e^{- x}

      Method #2

      1. Let u=exu = e^{- x}.

        Then let du=exdxdu = - e^{- x} dx and substitute du- du:

        1du\int 1\, du

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

          (1)du=1du\int \left(-1\right)\, du = - \int 1\, du

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

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

          So, the result is: u- u

        Now substitute uu back in:

        ex- e^{- x}

    Now evaluate the sub-integral.

  2. Use integration by parts:

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

    Let u(x)=2xu{\left(x \right)} = - 2 x and let dv(x)=ex\operatorname{dv}{\left(x \right)} = e^{- x}.

    Then du(x)=2\operatorname{du}{\left(x \right)} = -2.

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

    1. Let u=xu = - x.

      Then let du=dxdu = - dx and substitute du- du:

      eudu\int e^{u}\, du

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

        (eu)du=eudu\int \left(- e^{u}\right)\, du = - \int e^{u}\, du

        1. The integral of the exponential function is itself.

          eudu=eu\int e^{u}\, du = e^{u}

        So, the result is: eu- e^{u}

      Now substitute uu back in:

      ex- e^{- x}

    Now evaluate the sub-integral.

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

    2exdx=2exdx\int 2 e^{- x}\, dx = 2 \int e^{- x}\, dx

    1. Let u=xu = - x.

      Then let du=dxdu = - dx and substitute du- du:

      eudu\int e^{u}\, du

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

        (eu)du=eudu\int \left(- e^{u}\right)\, du = - \int e^{u}\, du

        1. The integral of the exponential function is itself.

          eudu=eu\int e^{u}\, du = e^{u}

        So, the result is: eu- e^{u}

      Now substitute uu back in:

      ex- e^{- x}

    So, the result is: 2ex- 2 e^{- x}

  4. Now simplify:

    (x22x2)ex\left(- x^{2} - 2 x - 2\right) e^{- x}

  5. Add the constant of integration:

    (x22x2)ex+constant\left(- x^{2} - 2 x - 2\right) e^{- x}+ \mathrm{constant}


The answer is:

(x22x2)ex+constant\left(- x^{2} - 2 x - 2\right) e^{- x}+ \mathrm{constant}

The answer (Indefinite) [src]
  /                                          
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 |  2  -x               -x    2  -x        -x
 | x *e  *1 dx = C - 2*e   - x *e   - 2*x*e  
 |                                           
/                                            
(x22x2)ex\left(-x^2-2\,x-2\right)\,e^ {- x }
The graph
0.001.000.100.200.300.400.500.600.700.800.902.5-2.5
The answer [src]
       -1
2 - 5*e  
25e12-5\,e^ {- 1 }
=
=
       -1
2 - 5*e  
25e2 - \frac{5}{e}
Numerical answer [src]
0.160602794142788
0.160602794142788
The graph
Integral of x^2*e^(-x)*dx dx

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