Homework SourseUse a half angle formula to find the exact value of cos pi8
Use a half angle formula to find the exact value of. cos (pi/8)
Use a half angle formula to find the exact value of. cos (pi/8)
Solution
cos(pi/8) = sqrt[(1 + cos(2(pi/8)))/2]
= sqrt[(1 + cos(pi/4))/2]
= sqrt[(sqrt(2) + 1)/2sqrt(2)]
= 0.92388
