Question

Sin patrat de 30°+cos patrat de 60°= cu 1 pe 2

Answer 1

${ \sin^{2}(30) } + { \cos^{2}(60) } = \frac{1}{2}$

$\sin(30) \times \sin(30) + \cos(60) \times \cos(60) = \frac{1}{2}$

$\frac{1}{2} \times \frac{1}{2} + \frac{1}{2} \times \frac{1}{2} = \frac{1}{2}$

$\frac{1}{4} + \frac{1}{4} = \frac{1}{2}$

$\frac{1 + 1}{4} = \frac{1}{2}$

$\frac{2}{4} = \frac{1}{2}$

$\frac{1}{2} = \frac{1}{2} \: (A)$