Bytelearn - cat image with glassesAI tutor

Welcome to Bytelearn!

Let’s check out your problem:

Evaluate x2e2xdx \int x^{2}e^{2x}dx

Full solution

Q. Evaluate x2e2xdx \int x^{2}e^{2x}dx
  1. Identify type of integral: Identify the type of integral.\newlineWe are asked to integrate a product of a polynomial function, x2x^2, and an exponential function, e2xe^{2x}. This suggests that we should use integration by parts.
  2. Apply integration by parts: Apply the integration by parts formula.\newlineThe integration by parts formula is udv=uvvdu\int u \, dv = uv - \int v \, du, where uu and dvdv are parts of the integrand that we choose. We need to choose uu and dvdv such that dudu and vv are easy to work with.
  3. Choose uu and dvdv: Choose uu and dvdv. Let's choose u=x2u = x^2 (which means du=2xdxdu = 2x \, dx after differentiation) and dv=e2xdxdv = e^{2x} \, dx (which means v=(1/2)e2xv = (1/2)e^{2x} after integration).
  4. Differentiate and integrate: Differentiate uu and integrate dvdv.\newlineDifferentiate uu to get du=2xdxdu = 2x \, dx.\newlineIntegrate dvdv to get $v = \left(\frac{\(1\)}{\(2\)}\right)e^{\(2\)x}.
  5. Substitute into formula: Substitute \(u\), \(du\), \(v\), and \(dv\) into the integration by parts formula.\(\newline\)Substitute the values into the formula to get:\(\newline\)\(\int x^2 e^{2x} dx = x^2 \cdot (\frac{1}{2})e^{2x} - \int(\frac{1}{2})e^{2x} \cdot 2x dx\)
  6. Simplify expression: Simplify the expression.\(\newline\)Simplify the integral to get:\(\newline\)\(\int x^2 e^{2x} \, dx = \frac{1}{2}x^2 e^{2x} - \int x e^{2x} \, dx\)
  7. Apply integration by parts again: Apply integration by parts again to the remaining integral.\(\newline\)We need to apply integration by parts to \(\int x e^{2x} \, dx\). Let's choose \(u = x\) (\(du = dx\)) and \(dv = e^{2x} dx\) (\(v = (1/2)e^{2x}\)).
  8. Differentiate and integrate: Differentiate \(u\) and integrate \(dv\) for the second application of integration by parts.\(\newline\)Differentiate \(u\) to get \(du = dx\).\(\newline\)Integrate \(dv\) to get \(v = \frac{1}{2}e^{2x}\).
  9. Substitute into formula again: Substitute \(u\), \(du\), \(v\), and \(dv\) into the integration by parts formula for the second time.\(\newline\)Substitute the values into the formula to get:\(\newline\)\(\int x e^{2x} dx = x \cdot (\frac{1}{2})e^{2x} - \int(\frac{1}{2})e^{2x} dx\)
  10. Simplify and integrate: Simplify the expression and integrate the remaining term.\(\newline\)Simplify the integral to get:\(\newline\)\(\int x e^{2x} dx = \frac{1}{2}x e^{2x} - \frac{1}{4}e^{2x}\)
  11. Substitute result back: Substitute the result from Step \(10\) back into the expression from Step \(6\).\(\newline\)Substitute the result to get:\(\newline\)\(\int x^2 e^{2x} dx = \frac{1}{2}x^2 e^{2x} - \left[\frac{1}{2}x e^{2x} - \frac{1}{4}e^{2x}\right]\)
  12. Simplify final expression: Simplify the final expression.\(\newline\)Simplify the expression to get:\(\newline\)\(\int x^2 e^{2x} dx = \frac{1}{2}x^2 e^{2x} - \frac{1}{2}x e^{2x} + \frac{1}{4}e^{2x} + C\), where \(C\) is the constant of integration.

More problems from Find derivatives using the quotient rule II