Identify integral: Identify the integral to be solved.We need to evaluate the integral of the function 6x3e−2x with respect to x. This is an integration problem that requires the use of integration by parts.
Apply integration by parts: Apply integration by parts. Integration by parts is given by the formula ∫udv=uv−∫vdu, where u and dv are parts of the integrand. We choose u=x3 (which will be differentiated) and dv=6e−2xdx (which will be integrated).
Differentiate and integrate: Differentiate u and integrate dv. Differentiating u gives us du=3x2dx. Integrating dv gives us v=−3e−2x (since the integral of e−2x is −21e−2x and we have a factor of 6).
Substitute into formula: Substitute u, v, du, and dv into the integration by parts formula.Now we have all the components to apply integration by parts:∫6x3e−2xdx=uv−∫vdu=(−3e−2x)(x3)−∫(−3e−2x)(3x2)dx=−3x3e−2x+9∫x2e−2xdx
Apply integration by parts again: Apply integration by parts again to the remaining integral.We need to integrate 9∫x2e−2xdx. We choose u=x2 and dv=9e−2xdx.Differentiating u gives us du=2xdx.Integrating dv gives us v=−29e−2x.
Substitute into formula again: Substitute u, v, du, and dv into the integration by parts formula for the second time.∫9x2e−2xdx=uv−∫vdu=(−29e−2x)(x2)−∫(−29e−2x)(2x)dx=−29x2e−2x+9∫xe−2xdx
Integrate exponential function: Apply integration by parts for the third time to the remaining integral.We need to integrate 9∫xe−2xdx. We choose u=x and dv=9e−2xdx.Differentiating u gives us du=dx.Integrating dv gives us v=−29e−2x.
Combine all parts: Substitute u, v, du, and dv into the integration by parts formula for the third time.∫9xe−2xdx=uv−∫vdu=(−29e−2x)(x)−∫(−29e−2x)dx=−29xe−2x+29∫e−2xdx
Combine all parts: Substitute u, v, du, and dv into the integration by parts formula for the third time.∫9xe−2xdx=uv−∫vdu=(−29e−2x)(x)−∫(−29e−2x)dx=−29xe−2x+29∫e−2xdxIntegrate the remaining exponential function.The integral of e−2x is −21e−2x, so we have:29∫e−2xdx=−49e−2x
Combine all parts: Substitute u, v, du, and dv into the integration by parts formula for the third time.∫9xe−2xdx=uv−∫vdu=(−29e−2x)(x)−∫(−29e−2x)dx=−29xe−2x+29∫e−2xdxIntegrate the remaining exponential function.The integral of e−2x is −21e−2x, so we have:29∫e−2xdx=−49e−2xCombine all parts to get the final answer.Now we combine all the parts from the previous steps:v0This is the final answer, where v1 is the constant of integration.
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