$sin^2\alpha+cos^2\alpha=1$
$sin^2\alpha=1-cos^2\alpha$
$sin^2\alpha=1-\bigg(\dfrac{3}{4}\bigg)^2$
$sin^2\alpha=\dfrac{7}{16}$
$sin\alpha=\dfrac{\sqrt[]{7}}{4}$
$tan\alpha=\dfrac{sin\alpha}{cos\alpha}=\dfrac{\sqrt[]{7}}{3}$
$cot\alpha=\dfrac{1}{tan\alpha}=\dfrac{3}{\sqrt[]{7}}$