The displacement \(x\) of a particle moving in one dimension under the action of a constant force is related to time \(t\) by the equation $$\(t=\sqrt{x}+3,\) where \(x\) is in meters and \(t\) is in seconds. What is the displacement of the particle from \(t=0~\text s\) to \(t = 6~\text s?\)

1. \(0\)
2. \(12~\text m\)
3. \(6~\text m\)
4. \(18~\text m\)

Given below are two statements: 

If the velocity of a particle is $\mathrm{v}=\mathrm{At}+{\mathrm{Bt}}^2$, where A and B are constants, then the distance travelled by it between 1s and 2s is?

$1.$ $3\mathrm{A}+7\mathrm{B}$
$2.$ $\frac{3\mathrm{A}}{2}+\frac{7\mathrm{B}}{3}$
$3.$ $\frac{\mathrm{A}}{2}+\frac{\mathrm{B}}{3}$
$4.$ $\frac{\mathrm{A}}{3}+\frac{\mathrm{B}}{2}$