How to find Fourier Series Coefficients I saw many solved examples about this topic but again I coudn't come up with any solutions about this question. How can I find the Fourier Series coefficients of the following signal ?

$x(t)=2 \cos(3\pi t) + \sin(100\pi t+\frac{\pi }{3})$

I know that; $\cos(θ)=\frac12 (e^{jθ} + e^{−jθ})$  and,
$\sin(θ)=\frac{1}{2j} (e^{jθ} - e^{−jθ})$

I also know that I should use
$$x(t) = \sum_{-\infty}^{\infty} a_{k} e^{jk(2\pi/T)t}$$

But I'm having trouble to define the fundamental period $T$ and the relation between sinusoidal terms and coefficients $a_k$, to sum all things together. Thanks to everyone...
First, recognise that the fundamental period of the signal x(t) (sum of two sinusoidals with periods 2/3 s and 1/50 s) is 2s. And the fundamental frequency, $f_0$, is 0.5 hz.  

Then considering the CT Fourier Series expansion of the periodic signal x(t) wrt its fundamental frequency $f_0$ given as $\sum_{-\infty}^{\infty}{a_k e^{jk2\pi f_0t}}$ you can  therefore find the coefficients corresponding to $2\cos(3\pi t)$ and $\sin(100\pi t + \pi/3)$ with k=3 and k=100 respectively. 

Then, by expressing the sinusoidals in terms of complex exponentials using the Euler's identity this becomes $a_3=1 ,~ a_{-3}= 1 , ~~a_{100} = e^{j\pi/3}/2j, ~~a_{-100} = -e^{-j\pi/3}/2j $  which can be further manipulated if you want a rectengular representation of the complex coefficient instead of the above mixed-polar one.

Assuming no errors made during the arithmetic.