[질문] 싸인75 코싸인75인지좀

sin75 = sin(45 + 30) = sin45cos30 + cos45sin30 = (1/√2 ) (√3 /2) + (1/√2 ) (1 /2)= √6 /4 + √2 /4= (√6 + √2 ) /4 = cos15