## Fundamentals of Physics Extended (10th Edition)

$t=-0.82$ s
To find t when $x(t)=0,$ we solve the $x(t)$ function and substitute $x(t)=0$ in the equation; $4.0-6.0t^{2}=0$ $4.0=6.0t^{2}$ $\displaystyle \frac{4.0}{6.0}=t^{2}$ $t=\sqrt{\frac{4.0}{6.0}}\approx\pm 0.82$ s So, the negative time at which x passes through the origin is $-0.82$ s.