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Question
Find the magnitude of angle A, if 2 cos2 A - 3 cos A + 1 = 0
Solution
2 cos2 A – 3 cos A + 1 = 0
2 cos2 A – cos A - 2cosA +1 = 0
cos A(2cos A – 1) – (2 cos A – 1) = 0
( 2 cosA – 1) (cos A – 1) = 0
2 cos A – 1 = 0 aand cos A – 1 = 0
cos A = `(1)/(2)` and cos A = 1
A = 60° and A = 0°
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