Line joining `A(bcosalpha,bsinalpha)` and `B(acosbeta,asinbeta)`, is produced to the point `M(x,y)` such that `AM:MB=b:a` then `xcos((alpha+beta)/2)+ysin((alpha+beta)/2) =`

Options

A. `a^(2)+b^(2)`
B. 0
C. 1
D. `-1`

Answer

B