Răspunsuri

2014-09-27T12:28:08+03:00
Pai sa consideram x=60 si y=30
cosx*cosy+sinx*siny=cos(x-y)
Deci, in cazul tau, cos 60*cos 30+sin 60*sin30=cos(60-30)=cos30=  \frac{ \sqrt{3} }{2}