a would be nice, but I desperately need parts b and c. AND DO NOT COPY THE ANSWER FROM CHEGG. I KNOW THERE IS ONE FOR THIS QUESTION BUT IT IS INCOMPLETE AND WRONG

SOLUTION
(b) Here impulse response of two system h1(t) and h2(t) are given out of which h2(t) is the causal system so for determining output response we are considering impulse response h2(t)
Given h2(t)=(cos2t)u(t-2)
For x(t)=u(t)-u(t-1) , y(t) will be calculated using Laplace transform.
Now taking Laplace of h2(t)= (½)(cos2t+1)u(t-2)
H2(s) =
=
= ...