1.1. Melody throws a netball into a net. The path of the ball from leaving Melody’s hand to passing through the net is modelled by the function

            $h(x)=1.8+1.2x-0.2{x}^{2}x\geq0$

where h m is the height of the netball above the ground and x m is the horizontal distance travelled.

Find the height of the ball when it horizontally half way from being thrown to reaching its maximum height.

1.2. The above model is valid for $0\leqx\leqk$ , where k m is the horizontal distance of the net from the player. The standard height of a netball hoop is $3.05m$.

Find the value of k. Give your answer to three significant figures.

1.3. Explain why the model is not valid for $x>k$.