I'm taking the introductory course to systems and signals and the mathematics of integration using the step function and Dirac's function
integral 1 http://i.snag.gy/gCPxu.jpg
and
problem 2 http://i.snag.gy/16JBP.jpg
For the first integral, I just don't know how to deal with u(t-4), the step function.
The other two questions i don't even know how to start. Thanks, any help would be appreciated