The velocity v in meters per second of a certain type of wave is given by v(h)=3 square root h

The rate of change will be given by:
v(h)=3√h=3h^0.5
The rate of change will be:
v'(h)=(3×0.5)x^-0.5=1.5x^-0.5
hence when h=2 meters, then the rate of change will be:
v'(h)=1.5×2^-0.5
v'(h)=1.061 m/s