if sin alpha=1/2 and cos beta=1/2 then alpha+beta=

 Solution:-given that sin alpha=1/2 ............(1)

and cos beta=1/2...........(2)

from(1)....

sin alpha=1/2  

sin alpha=sin30°

alpha=30°

from(2).........

cos beta=1/2 

cos beta=cos60°

beta= 60°

 alpha+beta=30°+60°=90° Ans.......