Group Abstract Group Abstract

Message Boards Message Boards

Mathematica not able to Integrate t*a*exp(-a*t) dt

GROUPS:
I have been trying to get Mathematica to integrate the function:


integral from 0 to infinity of  t*a*exp(-(a*t)) dt

This funtion clearly converges, and working the integral out by hand it comes to 

1/a 

However when I enter the integral into Mathematica it simply returns the input as if it cannot perform the integral. While playing around I eventually receieved a message from Mathematica claiming the integral of t does not converge. Could somebody please explain to me how I need to input this Integral to obtain the correct result, as the t*a*exp(-t*a) clearly does converge?

Any suggestions would be appreciated
I would like to apologise for my poor formatting, this is my first attempt at posting in this forum.
I am a very new user to Mathematica
POSTED BY: James Kirk
Answer
1 year ago
Check your syntax:

In[4]:= Integrate[t*a*Exp[-(a*t)], {t, 0, \}]


Out[4]= ConditionalExpression[1/a, Re > 0]
POSTED BY: David Reiss
Answer
1 year ago
thank you for your response,
could you plese explain the \ in your limit input?
POSTED BY: James Kirk
Answer
1 year ago