The dc gain and characteristic root locations are given for three different stable second-order lti systems. in each case derive the corresponding transfer function and determine the time to reach steady state. a. r1 = −2.5, r2 = −0.2, dc gain=0.5 b. r1 =−3,r2 =−10,dcgain=6 c. r1,2 = −2 ± j4, dc gain=125 d. r1,2 = −0.4 ± j1.6, dc gain = 0.02