y = A cos(Bx + C)
A - amplitude
\(\frac{2\pi}{B}\) - period
\(- \frac{C}{B}\) - phase shift
\(y=5\cos{( \frac{x}{2} + \frac{2\pi}{3} )}
\\
\\y=5\cos{( \frac{1}{2}x + \frac{2\pi}{3})}
\\
\\A=5,B= \frac{1}{2},C= \frac{2\pi}{3}\)
Amplitude: 5
Period: \(\frac{2\pi}{B}=\frac{2\pi}{\frac{1}{2}}=4\pi\)
Phase shift: \(- \frac{C}{B} =- \frac{\frac{2\pi}{3}}{\frac{1}{2}}= -\frac{4\pi}{3}\)