2arcsin√2/2-1/2arctg√3

π/3

Reason:

• arcsin(√2/2) = π/4, so 2·arcsin(√2/2) = π/2
• arctan(√3) = π/3, so (1/2)·arctan(√3) = π/6
• π/2 − π/6 = π/3