# Thread: can some one explain this

1. ## can some one explain this

it was sent to me , but not being a math person i dont get the joke
or am i totally daft?

2. I have not seen this but it looks to me like

$\displaystyle \left( \int_{-\infty}^{\infty} e^{-x^2}~dx \right)^2 =1^2=1$

3. $\displaystyle \int_{-\infty}^{+\infty} e^{-x^2} dx = \sqrt{\pi}$

Do you get it now?