Question

find cos x/2, given cosx=1/4, with 0 13 years ago

Answer 1

cosx = 2cos^2 (x/2) -1
1/4 = 2cos^2 (x/2) -1
5/4 = 2cos^2 (x/2)
5/2 = cos^2 (x/2)
\[cos (x/2) = \sqrt{5/2} =? \]

Answer 2

true ;

Answer 3

Actually I've given the answer :| Silly me to type that question mark!!!!

Answer 4

lool it causes me no problems marks