Calcolatore di integrali definiti e impropri

Il calcolatore cercherà di valutare l'integrale definito (cioè con estremi), inclusi quelli impropri, mostrando i passaggi.

Enter a function:

Integrate with respect to:

Enter a lower limit:

If you need `-oo`, type -inf.

Enter an upper limit:

If you need `oo`, type inf.

Please write without any differentials such as `dx`, `dy` etc.

If the calculator did not compute something or you have identified an error, or you have a suggestion/feedback, please contact us.

Solution

Your input: calculate $$$\int_{\infty}^{0}\left( x e^{- x^{2}} \right)dx$$$

First, calculate the corresponding indefinite integral: $$$\int{x e^{- x^{2}} d x}=- \frac{e^{- x^{2}}}{2}$$$ (for steps, see indefinite integral calculator)

Since the upper bound is less than the lower, according to the property of integrals, we can swap them and change the sign:

$$$\int_{\infty}^{0}\left( x e^{- x^{2}} \right)dx=-\int_{0}^{\infty}\left( x e^{- x^{2}} \right)dx$$$

Since there is infinity in the upper bound, this is improper integral of type 1.

To evaluate an integral over an interval, we use the Fundamental Theorem of Calculus. However, we need to use limit if an endpoint of the interval is special (infinite).

$$$\int_{0}^{\infty}\left( x e^{- x^{2}} \right)dx=\lim_{x \to \infty}\left(- \frac{e^{- x^{2}}}{2}\right)-\left(- \frac{e^{- x^{2}}}{2}\right)|_{\left(x=0\right)}=\frac{1}{2}$$$

Do not forget about the minus sign: $$$\int_{\infty}^{0}\left( x e^{- x^{2}} \right)dx=-\int_{0}^{\infty}\left( x e^{- x^{2}} \right)dx=- \frac{1}{2}$$$

Answer: $$$\int_{\infty}^{0}\left( x e^{- x^{2}} \right)dx=- \frac{1}{2}=-0.5$$$

Please try a new game Rotatly

Calcolatore di integrali definiti e impropri

Calcola integrali definiti e impropri passo dopo passo

Solution