How's the best way to approach this using integrals some way or the other? I am confused...

A rocket takes off in a path described by the equation $\displaystyle y= \frac{2}{3}(x^2 - 1)^\frac{3}{2}$. Find the distance travelled by the rocket (rounded to the nearest km) for $\displaystyle x= 4.6 km$, to $\displaystyle x= 6.7km$