~QUIZ~ . Note: Soal terlampir. . Syarat untuk menjawab soal : ● Dilarang jawaban berupa komentar spam atau asal²an. ● Dilarang copas jawaban dari google. ● Jawabannya harus disertai dengan penjelasan yang masuk akal. ● Gunakanlah kata-kata jawabanmu sendiri yang baik dan benar.
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Jawaban:
[tex]B.-2[/tex]
Pengerjaan Soal:
[tex] terlampir [/tex]
Jawab:
-2 (B)
Penjelasan:
[tex]\lim\limits_{x \to 0} \frac{2sin(x)+sin(2x)}{-2x} \\[/tex]
Jika menggunakan cara substitusi,
[tex]\lim\limits_{x \to 0} \frac{2sin(x)+sin(2x)}{-2x} \\\\= \frac{2sin(0)+sin(2(0))}{-2(0)} \\\\=\frac{2(0)+0}{0} \\\\=\frac{0}{0}[/tex]
Hasilnya 0/0, maka berlaku aturan L'Hôpital, di mana:
[tex]\boxed{ \lim\limits_{x \to c} \frac{f(x)}{g(x)} = \lim\limits_{x \to c} \frac{f'(x)}{g'(x)}}[/tex]
[tex]\lim\limits_{x \to 0} \frac{2sin(x)+sin(2x)}{-2x} \\\\=-\frac{1}{2} \cdot \lim\limits_{x \to 0} \frac{2sin(x)+sin(2x)}{x}\\\\=-\frac{1}{2} \cdot (\lim\limits_{x \to 0} \frac{2sin(x)}{x}+\lim\limits_{x \to 0} \frac{sin(2x)}{x})\\\\=-\frac{1}{2} \cdot (2\cdot \lim\limits_{x \to 0} \frac{sin(x)}{x} +\lim\limits_{x \to 0} \frac{sin(2x)}{x})[/tex]
Aplikasikan aturan L'Hôpital.
[tex]=-\frac{1}{2} \cdot (2\cdot \lim\limits_{x \to 0} \frac{cos(x)}{1} +\lim\limits_{x \to 0} \frac{2\cdot cos(2x)}{1})\\\\=-\frac{1}{2} \cdot (2\cdot \frac{cos(0)}{1} +\frac{2\cdot cos(2\cdot0)}{1} )\\\\=-\frac{1}{2} \cdot (2\cdot cos(0)+2\cdot cos(0) )\\\\=-\frac{1}{2} \cdot (2\cdot 1 +2\cdot 1 )\\\\=-\frac{2+2}{2} \\\\=-\frac{4}{2} \\\\\boxed{=-2}[/tex]