lu51
Sin x + cos x = 1 maka (sin x + cos x)^{2} = 1^{2} sin ^{2} x+ cos^{2} x + 2 sin x cos x = 1 1+ 2 sin x cos x = 1 2 sin x cos x = 0 sin 2x =0 maka 2x = arc 0 = 0, 180 ,360
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izharulhaq78
tapi cos 180 itu -1,
sin180 + cos180 - 1= 0
0 + (-1) - 1= 0
0 - 1 - 1= 0
-2 ≠ 0
maka (sin x + cos x)^{2} = 1^{2}
sin ^{2} x+ cos^{2} x + 2 sin x cos x = 1
1+ 2 sin x cos x = 1
2 sin x cos x = 0
sin 2x =0
maka 2x = arc 0 = 0, 180 ,360