What is the Inverse Laplace Transform of (9s+5)/(s2-9) with s>3?

[Hogger]

Homework Statement

Find the inverse Laplace Transform of (9s+5)/(s²-9) given s>3

Homework Equations

I have a table of Laplace Transforms.
it says "sinh at" goes with a/(s²-a²) and "cosh at" goes with s/(s²-a²)

The Attempt at a Solution

I know how to split it up and find the inverse Laplace Transform but I don't know what it means by "cosh". I assume it is some variation of cosine? Someone said it means degrees but I don't see how that would change the problem.

 

[Count Iblis]

cosh(x) = 1/2 [exp(x) + exp(-x)]


sinh(x) = 1/2 [exp(x) - exp(-x)]

 

[Hogger]

thanks, apparently the professor somewhat explained this but I missed it.