Error in asnwer? Finding the transfer function of a system

[toofle]

Homework Statement

Find the transfer function and the impulse response for the system:

y'(t) + y(t) = x(t)

x = {1 if 0<=t<1,0 1<=t}

Homework Equations

d/dt y(t) ~ sY(s) -y(0)

The Attempt at a Solution

I transform into the laplace-domain:
sY(s) - y(0) + Y(s) = X(s)
Y(s)(s+1) - 1 = X(s)

Here I can't get H(s)=Y(s)/X(s) beacuse of y(0)=1 and not 0.

The answer is H(s) = 1/(s+1) . then it is easy to get the impulse response by backtransforming to the timedomain so that's no problem.
But there must be an error in the answer or problem statement right?

 

[Mark44]

Homework Statement

Find the transfer function and the impulse response for the system:

y'(t) + y(t) = x(t)

x = {1 if 0<=t<1,0 1<=t}

Homework Equations

d/dt y(t) ~ sY(s) -y(0)

The Attempt at a Solution

I transform into the laplace-domain:
sY(s) - y(0) + Y(s) = X(s)

You have a mistake on the right side, in that you have not put in the function given as x(t).

x(t) = H(t) - H(t - 1), where H is the Heaviside function.

So $X(s) = \mathcal{L}(x(t)) = e^{-0} - e^{-s} = 1 - e^{-s}$

Y(s)(s+1) - 1 = X(s)

Now, substitute for X(s) above, and see how it come out.

Here I can't get H(s)=Y(s)/X(s) beacuse of y(0)=1 and not 0.

The answer is H(s) = 1/(s+1) . then it is easy to get the impulse response by backtransforming to the timedomain so that's no problem.
But there must be an error in the answer or problem statement right?