PROBLEM 1: Sketch the following signals (where r(t) is a ramp function and u(t) is a step function): a. f(t)=r(t+2)- 2r(t) + u(t − 2) - b. f(t)=2r(t+3) - 2r(t − 1) - 4u(t - 1) - 2r(t-3)+28(t −5) + 2r(t - 7) + 4u(t-7) c. f(t) = u(t2)u(10 - t) d. f(t) = e− e. f(t) = cos(r(t)) f. f(t)=r(cos(t)) - PROBLEM 2: Express the following in terms of singularity functions: 1 0 1 1 轉診 a) 2 3 4 1.5 1 0 1 12 3 0.5 -1 1 2 3 b) c) 1 2 1 0 1 2 3 4 2 0 1 2 3 4 d) e) f)