$0<\alpha <\dfrac{\pi}{2}$
$\Rightarrow sin\alpha > 0, cos\alpha >0$
$\Rightarrow sin\alpha=\dfrac{3}{4}$
$cos\alpha=\sqrt{1-sin^2\alpha}= \dfrac{\sqrt7}{4}$
$tan\alpha=\dfrac{sin\alpha}{cos\alpha}=\dfrac{3}{\sqrt7}$
$cot\alpha=\frac{1}{tan\alpha}=\dfrac{\sqrt7}{3}$
