Question

Dados cos a = 1/3 hallar sen a/2;siendo​

Answer 1

Se sabe que:

$\sin \dfrac{\alpha}{2}=\sqrt{\dfrac{1-\cos\alpha}{2}}$

$\sin \dfrac{\alpha}{2}=\sqrt{\dfrac{1-\frac{1}{3}}{2}}$

$\sin \dfrac{\alpha}{2}=\sqrt{\dfrac{\frac{2}{3}}{2}}$

$\sin \dfrac{\alpha}{2}=\sqrt{\dfrac{2}{6}}$

$\sin \dfrac{\alpha}{2}=\sqrt{\dfrac{1}{3}}$

$\sin \dfrac{\alpha}{2}=\dfrac{1}{\sqrt{3} }\cdot \dfrac{\sqrt{3} }{\sqrt{3} }$

$\boxed{\sin \dfrac{\alpha}{2}=\dfrac{\sqrt{3} }{3}}$