Bantu jawab dong, soalny mau dikumpul bsk

<p>Jawaban &nbsp;<strong>-½</strong></p><p>&nbsp;</p><p><strong>Pembahasan</strong></p><p>Konsep turunan 2 buah fungsi</p><p>u.v = u'v + uv'</p><p>&nbsp;</p><p>f(x) = (cos 2x. cos x) + (sin 2x. sin x)&nbsp;</p><p>f'(x) = (2. -sin 2x. cos x + cos 2x. -sin x) +&nbsp;</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; (2 cos 2x.sin x + sin 2x. cos x)&nbsp;</p><p>&nbsp; &nbsp; &nbsp; &nbsp; = -2 sin 2x. cos x - cos 2x. sin x + 2 cos 2x. sin x +&nbsp;</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; sin 2x. cos x</p><p>&nbsp; &nbsp; &nbsp; &nbsp; = -sin 2x. cos x + cos 2x. sin x</p><p>&nbsp;</p><p>f'(π/6) = -sin π/3. cos π/6 + cos π/3. sin π/6</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= -½√3. ½√3 &nbsp;+ &nbsp;½. ½</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= -¾ + ¼</p><p>&nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; &nbsp;= -½</p><p>&nbsp;</p>