pre-cal math help please?

[Electricity]

Find cos theta/2, given that sin theta= 1/4 and theta terminates in 0<theta< 90○.

a) √6/4
b) √8-2√15/4
c) √10/4
d) √8+2√15/4
im not getting the answer

 

[adavanzo1992]

put into your calculator inverse sin of 1/4 and that's your answer