This is for my trig class. Thanks for the help!
Given sintheta=4/5, theta lies in Quadrant II, find cos (theta/2)
Tutors, please sign in to answer this question.
sin x = 4/5
cos x = -3/5, by 3-4-5 Pythagorean triple and Q. II
cos x/2 = sqrt[(1/2)(1+cos x)] = sqrt[(1/2)(1-3/5)] = sqrt(5)/5