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(3x+4)*e^(3x)

Integral of (3x+4)*e^(3x) dx

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01e3x(3x+4)dx\int\limits_{0}^{1} e^{3 x} \left(3 x + 4\right)\, dx
Integral((3*x + 4)*E^(3*x), (x, 0, 1))
Detail solution
  1. There are multiple ways to do this integral.

    Method #1

    1. Let u=3xu = 3 x.

      Then let du=3dxdu = 3 dx and substitute dudu:

      (ueu3+4eu3)du\int \left(\frac{u e^{u}}{3} + \frac{4 e^{u}}{3}\right)\, du

      1. Integrate term-by-term:

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

          ueu3du=ueudu3\int \frac{u e^{u}}{3}\, du = \frac{\int u e^{u}\, du}{3}

          1. Use integration by parts:

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

            Let u(u)=uu{\left(u \right)} = u and let dv(u)=eu\operatorname{dv}{\left(u \right)} = e^{u}.

            Then du(u)=1\operatorname{du}{\left(u \right)} = 1.

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

            1. The integral of the exponential function is itself.

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

            Now evaluate the sub-integral.

          2. The integral of the exponential function is itself.

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

          So, the result is: ueu3eu3\frac{u e^{u}}{3} - \frac{e^{u}}{3}

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

          4eu3du=4eudu3\int \frac{4 e^{u}}{3}\, du = \frac{4 \int e^{u}\, du}{3}

          1. The integral of the exponential function is itself.

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

          So, the result is: 4eu3\frac{4 e^{u}}{3}

        The result is: ueu3+eu\frac{u e^{u}}{3} + e^{u}

      Now substitute uu back in:

      xe3x+e3xx e^{3 x} + e^{3 x}

    Method #2

    1. Rewrite the integrand:

      e3x(3x+4)=3xe3x+4e3xe^{3 x} \left(3 x + 4\right) = 3 x e^{3 x} + 4 e^{3 x}

    2. Integrate term-by-term:

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

        3xe3xdx=3xe3xdx\int 3 x e^{3 x}\, dx = 3 \int x e^{3 x}\, dx

        1. Use integration by parts:

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

          Let u(x)=xu{\left(x \right)} = x and let dv(x)=e3x\operatorname{dv}{\left(x \right)} = e^{3 x}.

          Then du(x)=1\operatorname{du}{\left(x \right)} = 1.

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

          1. Let u=3xu = 3 x.

            Then let du=3dxdu = 3 dx and substitute du3\frac{du}{3}:

            eu3du\int \frac{e^{u}}{3}\, du

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

              False\text{False}

              1. The integral of the exponential function is itself.

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

              So, the result is: eu3\frac{e^{u}}{3}

            Now substitute uu back in:

            e3x3\frac{e^{3 x}}{3}

          Now evaluate the sub-integral.

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

          e3x3dx=e3xdx3\int \frac{e^{3 x}}{3}\, dx = \frac{\int e^{3 x}\, dx}{3}

          1. Let u=3xu = 3 x.

            Then let du=3dxdu = 3 dx and substitute du3\frac{du}{3}:

            eu3du\int \frac{e^{u}}{3}\, du

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

              False\text{False}

              1. The integral of the exponential function is itself.

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

              So, the result is: eu3\frac{e^{u}}{3}

            Now substitute uu back in:

            e3x3\frac{e^{3 x}}{3}

          So, the result is: e3x9\frac{e^{3 x}}{9}

        So, the result is: xe3xe3x3x e^{3 x} - \frac{e^{3 x}}{3}

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

        4e3xdx=4e3xdx\int 4 e^{3 x}\, dx = 4 \int e^{3 x}\, dx

        1. Let u=3xu = 3 x.

          Then let du=3dxdu = 3 dx and substitute du3\frac{du}{3}:

          eu3du\int \frac{e^{u}}{3}\, du

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

            False\text{False}

            1. The integral of the exponential function is itself.

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

            So, the result is: eu3\frac{e^{u}}{3}

          Now substitute uu back in:

          e3x3\frac{e^{3 x}}{3}

        So, the result is: 4e3x3\frac{4 e^{3 x}}{3}

      The result is: xe3x+e3xx e^{3 x} + e^{3 x}

    Method #3

    1. Rewrite the integrand:

      e3x(3x+4)=3xe3x+4e3xe^{3 x} \left(3 x + 4\right) = 3 x e^{3 x} + 4 e^{3 x}

    2. Integrate term-by-term:

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

        3xe3xdx=3xe3xdx\int 3 x e^{3 x}\, dx = 3 \int x e^{3 x}\, dx

        1. Use integration by parts:

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

          Let u(x)=xu{\left(x \right)} = x and let dv(x)=e3x\operatorname{dv}{\left(x \right)} = e^{3 x}.

          Then du(x)=1\operatorname{du}{\left(x \right)} = 1.

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

          1. Let u=3xu = 3 x.

            Then let du=3dxdu = 3 dx and substitute du3\frac{du}{3}:

            eu3du\int \frac{e^{u}}{3}\, du

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

              False\text{False}

              1. The integral of the exponential function is itself.

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

              So, the result is: eu3\frac{e^{u}}{3}

            Now substitute uu back in:

            e3x3\frac{e^{3 x}}{3}

          Now evaluate the sub-integral.

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

          e3x3dx=e3xdx3\int \frac{e^{3 x}}{3}\, dx = \frac{\int e^{3 x}\, dx}{3}

          1. Let u=3xu = 3 x.

            Then let du=3dxdu = 3 dx and substitute du3\frac{du}{3}:

            eu3du\int \frac{e^{u}}{3}\, du

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

              False\text{False}

              1. The integral of the exponential function is itself.

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

              So, the result is: eu3\frac{e^{u}}{3}

            Now substitute uu back in:

            e3x3\frac{e^{3 x}}{3}

          So, the result is: e3x9\frac{e^{3 x}}{9}

        So, the result is: xe3xe3x3x e^{3 x} - \frac{e^{3 x}}{3}

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

        4e3xdx=4e3xdx\int 4 e^{3 x}\, dx = 4 \int e^{3 x}\, dx

        1. Let u=3xu = 3 x.

          Then let du=3dxdu = 3 dx and substitute du3\frac{du}{3}:

          eu3du\int \frac{e^{u}}{3}\, du

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

            False\text{False}

            1. The integral of the exponential function is itself.

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

            So, the result is: eu3\frac{e^{u}}{3}

          Now substitute uu back in:

          e3x3\frac{e^{3 x}}{3}

        So, the result is: 4e3x3\frac{4 e^{3 x}}{3}

      The result is: xe3x+e3xx e^{3 x} + e^{3 x}

  2. Now simplify:

    (x+1)e3x\left(x + 1\right) e^{3 x}

  3. Add the constant of integration:

    (x+1)e3x+constant\left(x + 1\right) e^{3 x}+ \mathrm{constant}


The answer is:

(x+1)e3x+constant\left(x + 1\right) e^{3 x}+ \mathrm{constant}

The answer (Indefinite) [src]
  /                                     
 |                                      
 |            3*x             3*x    3*x
 | (3*x + 4)*E    dx = C + x*e    + e   
 |                                      
/                                       
e3x(3x+4)dx=C+xe3x+e3x\int e^{3 x} \left(3 x + 4\right)\, dx = C + x e^{3 x} + e^{3 x}
The graph
0.001.000.100.200.300.400.500.600.700.800.900200
The answer [src]
        3
-1 + 2*e 
1+2e3-1 + 2 e^{3}
=
=
        3
-1 + 2*e 
1+2e3-1 + 2 e^{3}
-1 + 2*exp(3)
Numerical answer [src]
39.1710738463753
39.1710738463753
The graph
Integral of (3x+4)*e^(3x) dx

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