How do you solve #2cos^2x-5cosx+2=0#?
1 Answer
May 30, 2015
Call cos x = t
2t^2 - 5t + 2 = (2t - 1)(t - 2)
Solve the 2 basic trig equations:
a.
b. t = cos x = 2. Rejected since > 1
Call cos x = t
2t^2 - 5t + 2 = (2t - 1)(t - 2)
Solve the 2 basic trig equations:
a.
b. t = cos x = 2. Rejected since > 1