Question

find the exact solution of cos 7pi/8

Answer 1

-0.125

Answer 2

:( this is what the answer shows in the exam review guide for trig

\[-\sqrt{1/2-1/\sqrt(3)}\]

Answer 3

@shamil98

Answer 4

what would you like me to do :)

Answer 5

-1/2-1/3 ??? I would try looking it up

Answer 6

i did :( my math department at OSU sucks and makes their own problems

Answer 7

i did send that shami98 a message though :) I hope he knows

Answer 8

Yea

Answer 9

hint: you need to use the double angle formula

Answer 10

i do? O:

Answer 11

the cos double angle or half angle? :)

Answer 12

half angle works too

Answer 13

also the identity cos(x)=-cos(pi-x) might help