CT signal
$ x(t) = 2 + cos({\frac{2\pi t}{3}})+ 4sin({\frac{5\pi t}{3}})\, $
Coefficients
$ cos({\frac{2\pi t}{3}}) = \frac{1}{2}e^({\frac{j2\pi t}{3}}}) + \frac{1}{2}e^({\frac{-j2\pi t}{3}}}) $
$ x(t) = 2 + cos({\frac{2\pi t}{3}})+ 4sin({\frac{5\pi t}{3}})\, $
$ cos({\frac{2\pi t}{3}}) = \frac{1}{2}e^({\frac{j2\pi t}{3}}}) + \frac{1}{2}e^({\frac{-j2\pi t}{3}}}) $