Problem 2: The roots of the characteristic equations of several systems are given below. Determine in each case if the set of roots represents stable, marginally stable, or unstable systems. (a)-1,-2 (d) -1+j, -1-j (b) -3, -2, 0 (c)-1, +1 (e) 2,-1,-3 (g)-6,-4, 7 (h) -j,j, -1, 1 (f) -2+ j,-2-j, 2j, -2 j - (i) 2+3j, 2-3j,-2 Problem 3: The differential equation of an integrator may be written as follows: dy/dt = u. Determine if an integrator is stable.