Question

com o auxilio da tabela dos arcos notáveis calcule: a) seno 120

Answer 1

Olá!

$\\ \sin 120^o = \\\\ \sin (90^o + 30^o) = \\\\ \sin 90^o \cdot \cos 30^o + \sin 30^o \cdot \cos 90^o = \\\\1\cdot\frac{\sqrt{3}}{2}+\frac{1}{2}\cdot0=\\\\ \boxed{\frac{\sqrt{3}}{2}}$