Jawabanmu

2014-05-31T14:16:46+07:00
3 cos² A + 5 cos A - 2 = 0
(3 cos A - 1 )(cos A + 2) = 0
cos A = 1/3 (oke) atau cos A = -2 (tidak memenuhi)

cos A = 1/3
maka sin A = 2√2 / 3
tan A = 2√2