cos(x+兀) cos负x为什么等于cos x cos(x+π) cos(π+x) cos(x+y)= cos(x+2/π) cos(x+π/2) cos(π/2+x) cos兀等于多少 cos(x+y) cos2兀是多少 cos兀是多少 cos2兀等于多少 cos3兀等于多少 cos兀/6 cos(π/6) cos x cos兀等于 cos兀 cos(π/8) cos兀/2 cos–1等于cos1吗 cos(π/2) cos(x) cosπ+x cos1/x cos兀/3 cos(π/4) cos(a加b) cos(90+a) cos (a+b) cos(a+b)= cos2兀 cos2分之兀 cos2兀的值 cos3兀 cos 1等于多少 mcbxshi _ cos cos方x等于 1 cos 1/cos cos=0.8 cos72等于多少 cos(a+b)等于 cos(a+b) cos(a,b) cos
