(a) $H = \frac{u^{2}\sin^{2}\theta}{2g}\ $and $T = \frac{2u\sin\theta}{g}$ So $\frac{H}{T^{2}} = \frac{u^{2}\sin^{2}\theta/2g}{4u^{2}\sin^{2}\theta/g^{2}} = \frac{g}{8} = \frac{5}{4}$
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