(Sin x-1) (2 cos x+1)=0
Matematika
triazuliana994
Pertanyaan
(Sin x-1) (2 cos x+1)=0
1 Jawaban
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1. Jawaban ramadhana21
Bring stuff on the other side of the equation:
cos^2 x = 1 - sin^2 x
2cos^2 x - sin x - 1 = 0
2(1 - sin^2 x) - sin x - 1 = 0
2sin^2 x + sin x - 1 = 0
Factor this
(2 sin x - 1)(sin x +1) = 0
2 sin x - 1 = 0 or sin x +1 = 0
sin x = 1, and sin x = -1
Answers:
pi/6, and 3pi/2, adding 2pi times a constant, for each trip around the unit circle.