Recent content by alex73

ok, i just noticed where i went wrong. Using f(0)=1 I think its: (-s-12)/(s^2 +4) Is this correct? Thanks. I like that you don't just tell me the answer, it helps me improve and makes you feel better when you have done it yourself.

Normally they use 1. But i can't get it correct if i use that. Unless i am doing something wrong. here is how i am doing it: 3(-1+sF(s))-F(s) 3-3sF(s)-F(s) (-3s-1)*F(s)+3 ((-3s-1)*s/(s^2 +4)) +3 (-3s^2 - s + 3s^2 +12)/(s^2 +4) = (-s+12)/(s^2 +4)

thanks, How do you work out what f(0) is? i thought it was f(t) at 0. And 0 on the cos2x graph is 1, isn't it? Or am i incorrect on how to work it out. On the first question i get to here: 4(s/((s+2)^2 +4). ok i just worked backwards and i think the answer is: 4e^(-2t) * (cos2t-sin2t) is this...

Ok i have two questions, one i am unsure of and one i don't have a clue how to correctly find it. Homework Statement You have to work out the inverse function of: 4s/ s^2+4s+8 The Attempt at a Solution I think the answer is: 4e^(-2t)*(cos2t+sin2t) Is this correct? Homework...