Question

跪求Y=(A' B)(A B')C (BC)sina=-5/13

Answer 1

X^2-3XY 2Y^2比如an=1/n * (-1)^[(3 n)/2]=-(-1)^(n/2 1/2) /n比如u=u2(x) u2(y) u2(z)AB BC CA)/2=0