Sin (x+210)+sin(x-210)=1/2√3
Matematika
dinaDwitica93
Pertanyaan
Sin (x+210)+sin(x-210)=1/2√3
1 Jawaban
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1. Jawaban tjahjaditeddy
sin a + sin b = 2 sin 1/2(a + b). cos 1/2(a - b)
Sin (x+210)+sin(x-210)=1/2√3
2 sin 1/2([x+210]+[x-210]). cos 1/2([x+210]-[x-210]) = 1/2√3
2 sin 1/2([2x]). cos 1/2([420]) = 1/2√3
2 sin x.cos 210 = 1/2√3
2 sin x.(-1/2√3) = 1/2√3
2 sin x = -1
sin x = -1/2
kuadran 3; x = 180+30= 210
kuadran 4; x = 360-30= 330