The displacement x of a particle moving in one direction is given by $\mathrm{t}=\sqrt{\mathrm{x}}+3$, where x in meter and t in sec. What is its displacement when its velocity is zero

Given  $\mathrm{t}=\sqrt{\mathrm{x}}+3$

⇒$\sqrt{x}=t-3$

Squaring both sides, x = t²−6t+9

Velocity, v = dx/dt = 2t−6

For velocity, v to be equal to zero, 2t − 6 = 0 ⇒t = 3 s

At t = 3 s, displacement, x = t² − 6t + 9 = 3² − 6×3 + 9 = 0