# Thread: Basic Transform of Derivative Help?

1. ## Basic Transform of Derivative Help?

A simple problem to start to see the process would be helpful

Find L{f'(t)} if L{f(t)} = 1/(s-2)^2 initial condition f(0)=0

2. Originally Posted by chief27
A simple problem to start to see the process would be helpful

Find L{f'(t)} if L{f(t)} = 1/(s-2)^2 initial condition f(0)=0
Go to your table of Laplace Transforms (or use Google if you don't have one) and get the formula for L{f'(t)}. Substitute the given information into it.

3. I looked and couldn't find any formula for it not even in my diff eq text book.

4. Originally Posted by chief27
I looked and couldn't find any formula for it not even in my diff eq text book.

It was when I tried: Laplace Transform of Derivative

(Maybe your book has pages torn out - you better check because there might be other formulae you need that are on pages that are missing).

5. i just found that not 1 minute ago lol

using that formula for a first deriv I got

L[f'(t)]=sL[1/(s-2)^2] - 0

is that all I have to do?

6. Originally Posted by chief27
i just found that not 1 minute ago lol

using that formula for a first deriv I got

L[f'(t)]=sL[1/(s-2)^2] - 0

is that all I have to do?
Using the formula: $L[f'(t)] = s L[f(t)] - f(0) = s \cdot \frac{1}{(1 - s)^2} - 0 = \frac{s}{(1 - s)^2}$.

7. thanks for the help