SubArea: Sine, cosine, tangent and cotangentLevel: BProject ID: 1003076510Accepted: 1Clonable: 0Easy: 1If the angle \( \alpha\in[0;90^{\circ}] \) and \( \sin\alpha = 0.5 \), then \( \cos \alpha \) is equal to:\( \frac{\sqrt3}2 \)\( -\frac{\sqrt{3}}2 \)\( -\frac12 \)\( \frac12 \)
