jika cotx.cosx-sinx=cosx, maka nilai tan 2x=... A. -2 B. -1 C. 0 D. 1 E. 2 Fast respon

TRIgonomeTRI

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cos 2x = cos² x - sin² x
cot x = cos x /sin x
sin 2x = 2 sin x cos x
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cot x . cos x - sin x = cos x
(cos x /sin x) . cos x - sin² x /sin x = cos x
(cos² x - sin² x)/sin x = cos x
Kdua ruas kalikan sin x
cos 2x = sin x cos x
cos 2x = 1/2 . sin 2x
sin 2x/cos 2x = 2/1
tan 2x = 2 ✔