Exponential converge?

1. Feb 26, 2008

Mattofix

[SOLVED] exponential converge?

1. The problem statement, all variables and given/known data

does the integral from 0 to infinty of exp(-x) converge - if so, is it just accepted or does it need to proven?

2. Feb 26, 2008

sutupidmath

$$\int_0^{\infty}e^{-x}dx$$ it is convergent and it needs to be proven!
you might want to go like this, although you haven't shown your work at all!!!!

$$\lim_{b \rightarrow \infty} \int_0^{b}e^{-x}dx$$, now can you find an antiderivative for the integrand $$e^{-x}$$

3. Feb 26, 2008

Mattofix

thanks - yeah, sorry i havnt shown any working- i know it converegs to 1 though.

4. Feb 26, 2008

sutupidmath

Yeah after u evaluate that limit, you will end up with 1. good job!