# Laplace transform with f(t)=t

1. Nov 3, 2009

### Will_M

1. The problem statement, all variables and given/known data
This is my first post, so bear with me. I have seen others who have posted their questions and the problem looked like it was typed in mathcad or something. How do I do that?

Ok so I'm trying to figure out how to solve a piecewise Laplace transform when f(t)=t

the actual problem is

f(t)={t, 0<t<1 (should be read as 0 less than or equal to t...)
{1, t>1 (should be read as t greater than or equal to 1)

2. Relevant equations

L{f(t)}= integral of e-stf(t)dt

3. The attempt at a solution

My attempt. Please help me figure out how I can make this show up as it would in person. (with the integral sign, exponents, etc.)

=integral from 0 to 1 of e-sttdt + integral from 1 to infinity of e-stdt

=-1/s(e-s)(1/2) + 1/s(e-s)

=(-e-s/2) + ((1/s)e-s)

the correct answer should be =(1/s2) - (e-s/s2)

I appreciate the patience everyone.

2. Nov 3, 2009

### Will_M

wait wait don't tell me. I've almost got it.

3. Nov 3, 2009

### Will_M

I'm an idiot and forgot basic calculus rules.

/thread

Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook