I am trying to find State Transition Matrix (STM) in MATLAB using "expm(A*t)" command. For real roots, its fine, but when its complex eigenvalues, its going into piecewise mode and not giving the STM in terms of sin or cosine.
A = [0 1 0; 0 0 1; -2 -3 -5];
A_STM = expm(A*t)
For this I am getting following STM in truncated form as attached (One Real and Two Complex Conjugate):
But I want answer in the following form (Not for above example), from MATLAB -
Can somebody guide, help?