Tentukan Hp cos 4x-cos2x = 0, pada interval 0
Matematika
masfaridz
Pertanyaan
Tentukan Hp cos 4x-cos2x = 0, pada interval 0<x<2phi
1 Jawaban
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1. Jawaban Anonyme
TriGonoMetRi
cos 4x - cos 2x = 0
2 cos² 2x - 1 - cos 2x = 0
(2 cos 2x + 1)(cos 2x - 1) = 0
2 cos 2x + 1 = 0
cos 2x = -1/2
2x = ± 120° + k.360°
x = ± 60° + k.180°
x = 60° , 120° , 240° , 300°
atau
2x = ± 240 + k.360°
x = ± 120° + k.180°
x = 60° , 120° , 240° , 300°
cos 2x - 1 = 0
cos 2x = 1
x = k.180°
x = 0° , 180° , 360°
Interval : 0° < x < 360°
NiLai x yg memenuhi :
60° , 120° , 180° , 240° , 300°