V = X’ = Ω ACOS( Ω T + Φ+ Π /2 );

3. - ON TAP VAT LY 12 BT TRAC NGHIEM THEO CHU DE THEO DE THITN CAC NAM
ON TAP VAT LY 12 BT TRAC NGHIEM THEO CHU DE THEO DE THITN CAC NAM

3. Vận tốc: v = x’ = ω Acos( ω t + ϕ+ π /2 );