sina + sinb = 1/root2.
cosa + cosb = 1.
(sina)^2 + (cosa)^2 = 1 = (1/root2 - sinb)^2 + (1-cosb)^2.
1/2 + (sinb)^2 - (root2)(sinb) + 1 + (cosb)^2 - 2cosb = 1.
3/2 - root2(sinb) = 2cosb.
9/4 + 2(sinb)^2 - 3(root2)(sinb) = 4 - 4(sinb)^2.
from here we can get, sinb. then we can get all what we want easily.
if we put x = sinb then we get

or 