The wave function of a

$10$ points

sinusoidal wave generated on a string is given by: $y(x,t)=0\mathrm{.}2sin(2x+4t+).$Att$=0,an$ element of the string at $x=0$ has a vertical displacement of $0\mathrm{.}1$ m and is moving down. The phase constant is:

$=\frac{}{3}$

$=2\frac{}{3}$

$=\frac{}{6}$

$=5\frac{}{6}$