x=0.05cos(2πt+1/3π)是x=0.05cos(2πt+π/3) m 吧?-0.025=0.05cos(2πt+π/3),,则 cos(2πt+π/3)=-0.5 .,则2πt+π/3=2π/3 ,解得 t=1/6 (s)
x=0.05cos(2πt+1/3π)是x=0.05cos(2πt+π/3) m 吧?-0.025=0.05cos(2πt+π/3),,则 cos(2πt+π/3)=-0.5 .,则2πt+π/3=2π/3 ,解得 t=1/6 (s) 。