Happy Birthday Carina

$$ x(t) = A_1 \sin(f_1 t + p_1) e^{-d_1 t} + A_2 \sin(f_2 t + p_2) e^{-d_2 t} $$ $$ y(t) = A_3 \sin(f_3 t + p_3) e^{-d_3 t} + A_4 \sin(f_4 t + p_4) e^{-d_4 t} $$