Complexify the ODE below in order to find its particular solution:

y+7y+12y=e4tcos(2t)\displaystyle {y}{''}+{7}{y}'+{12}{y}={e}^{{{4}{t}}}{\cos{{\left({2}{t}\right)}}}

yp(t)\displaystyle {y}_{{p}}{\left({t}\right)} =