Question

me ajudem pfvvvvvvvvvvv

Answer 1

               Triângulos Oblíquos

Nós aplicamos a lei dos cossenos:

$(\sqrt{4} )^{2} =(\sqrt{2} )^{2} +(\sqrt{3} )^{2} -2(\sqrt{2} )(\sqrt{3} )(cos"a")\\\\\\4=2+3-2\sqrt{6}(cos"a")\\\\\\4=5 -2\sqrt{6}(cos"a")\\\\\\2\sqrt{6}(cos"a")=5-4\\\\\\2\sqrt{6}(cos"a")=1\\\\\\cos"a"=\dfrac{1}{2\sqrt{6} } \\\\\\\texttt{Nos racionalizamos:}\\\\cos"a"=\dfrac{1*\sqrt{6} }{2\sqrt{6} *\sqrt{6} } \\\\\\cos"a"=\dfrac{\sqrt{6} }{2*6} \\\\\\\boxed{\bold{cos"a"=\dfrac{\sqrt{6} }{12} }}$

Resposta chave A