If P`(sin theta, 1//sqrt(2)) and Q(1//sqrt(2), cos theta), -pi le theta le pi` are two points on the same side of the line x-y=0, then `theta` belongs to the interval
A. `(-pi//4,pi//4)uu(pi//4,3pi//4)`
B. `(-pi//4,pi//4)`
C. `(pi//4,pi//4)`
D. none of these
