Question 725548: 2cos^2theta-5costheta-3=0
Answer by nshah11(47)   (Show Source):
You can put this solution on YOUR website! 2cos^2(t) - 5cos(t) - 3 = 0
2cos^2(t) - 6cos(t) + cos(t) - 3 = 0
2cos(t)(cos(t) - 3) + cos(t) - 3 = 0
(2cos(t) + 1)(cos(t) - 3) = 0
cos(t) = 3 (Not possible since cos(t) ranges from -1 to 1).
cos(t) = -1/2 => t = 2pi/3, 4pi/3 on the interval [0, 2pi].
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