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Math Help - What is the derivative of xe^(2x)?

  1. #1
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    What is the derivative of xe^(2x)?

    What is the derivative of x*e^(2x)?

    I know that I have to use integration by parts. However, I am not sure if I got the right answer.

    Thank you!
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  2. #2
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    Re: What is the derivative of xe^(2x)?

    The first derivative is e^(2x)[1+2x] and the second is 4e^(2x)[x+1]
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  3. #3
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    Re: What is the derivative of xe^(2x)?

    As far as my knowledge is concerned, The derivative can be calculated by

    using d/dx(uv) = u dv/dx + v du/dx

    d/dx(xe^2x) = x d/dx(e^2x) + e^2x as d/dx x = 1

    = 2x e^2x + e^2x as d/dx(e^y) = e^y dy/dx [using chain rule]
    Therefore, the derivative of xe^(2x)=1.
    Hope this is useful.



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  4. #4
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    Re: What is the derivative of xe^(2x)?

    Quote Originally Posted by remutyte View Post
    What is the derivative of x*e^(2x)?

    I know that I have to use integration by parts. However, I am not sure if I got the right answer.

    Thank you!
    What, exactly is the question? You first ask about the derivative but then refer to integration.

    If the question is about the derivative, you use the product rule: (xe^x)'= (x)'e^x+ x(e^x)'= e^x+ xe^x= (x+ 1)e^x.

    If the question is about the integral, you use integration by parts. Let u= x, dv= e^xdx. Then du= dx, v= e^x.
    \int xe^x dx= xe^x- \int e^x dx= xe^x- e^x+ C= (x- 1)e^x+ C.
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