Ví dụ 2:
a)\(x=-5cos\left(3\pi t+\dfrac{\pi}{3}\right)\)
Biên độ: \(A=-5cm\)
Tần số: \(f=\dfrac{1}{T}=\dfrac{\omega}{2\pi}=\dfrac{3\pi}{2\pi}=1,5Hz\)
Pha ban đầu: \(\varphi_0=\dfrac{\pi}{3}\left(rad\right)\)
b)\(x=-4sin\left(4\pi t+\dfrac{\pi}{6}\right)=4cos\left(4\pi t+\dfrac{\pi}{6}+\dfrac{\pi}{2}\right)=4cos\left(4\pi t+\dfrac{2\pi}{3}\right)\)
Biên độ: \(A=4cm\)
Tần số: \(f=\dfrac{\omega}{2\pi}=\dfrac{4\pi}{2\pi}=2Hz\)
Pha ban đầu: \(\varphi_0=\dfrac{2\pi}{3}\left(rad\right)\)