question_answer

If \[\cos (A-B)=sin(A+B)=\frac{1}{2},\] where A and B are positive, then smallest positive value of A + B (in degrees) is

A) \[45{}^\circ \]

B) \[60{}^\circ \]

C) \[105{}^\circ \]

D) \[150{}^\circ \]