S=7A=3.2.A+A
t=3.\(\dfrac{T}{2}\)+△t
Sdư=2A(1-cos(φmax/2))=A
=>φmax=120
=>△t=T/3
=>t=3T/2+T/3=11T/6
Mình sữa lại rồi đấy
Có S=7A=2.3A+A
t=2.\(\dfrac{T}{2}\)+△t
Sdư=2A(1-cos\(\dfrac{\varphi max}{2}\))=A
=>φmax=120
△tmax=△φmax.T/2π=T/3
t=T+T/3=\(\dfrac{4}{3}T\)