53. Agar cosα=3/4 ga teng bo‘lsa, sinα ni toping.

\(\sin\alpha=\sqrt{1-\cos^2\alpha}=\sqrt{1-\frac{9}{16}}=\sqrt{\frac{7}{16}}=\frac{\sqrt7}{4}\).

Javob: \(\frac{\sqrt7}{4}\) (C).