Exercise Zone : Limit [3]

Table of Contents
Berikut ini adalah kumpulan soal mengenai Limit. Jika ingin bertanya soal, silahkan gabung ke grup Telegram, Signal, Discord, atau WhatsApp.

Tipe:

StandarSNBTHOTS


No.

Buktikan limit fungsi berikut secara definisi \displaystyle\lim_{(x,y)\to(3,2)}(3x-4y)=1
ALTERNATIF PENYELESAIAN
Cari δ < 0 sedemikian rupa sehingga
{0\lt\sqrt{(x-3)^2+(y-2)^2}\lt\delta\Rightarrow|(3x-4y)-1|\lt\epsilon}

\sqrt{(x-3)^2+(y-2)^2}\lt\delta didapat |x − 3| < δ dan |y − 2| < δ. Ambil \delta=\dfrac{\epsilon}7

{|3x-4y-1|\lt|3x-9-4y+8|\lt3|x-3|+4|y-2|\lt3\delta+4\delta=7\delta=7\left(\dfrac{\epsilon}7\right)=\epsilon}
Jadi, terbukti bahwa \displaystyle\lim_{(x,y)\to(3,2)}(3x-4y)=1.

No.

Diketahui f(x) = x2 − 1. Tentukan nilai dari \displaystyle\lim_{p\to0}\dfrac{f(2+p)-f(2)}p
ALTERNATIF PENYELESAIAN
\begin{aligned} \displaystyle\lim_{p\to0}\dfrac{f(2+p)-f(2)}p&=\displaystyle\lim_{p\to0}\dfrac{(2+p)^2-1-\left(2^2-1\right)}p\\[3.8pt] &=\displaystyle\lim_{p\to0}\dfrac{4+4p+p^2-1-3}p\\[3.8pt] &=\displaystyle\lim_{p\to0}\dfrac{4p+p^2}p\\[3.8pt] &=\displaystyle\lim_{p\to0}(4+p)\\ &=4+0\\ &=\boxed{\boxed{4}} \end{aligned}
Jadi, \displaystyle\lim_{p\to0}\dfrac{f(2+p)-f(2)}p=4.

No.

\displaystyle\lim_{x\to0}\dfrac{x}{\sqrt{5-x}-\sqrt5}=....
ALTERNATIF PENYELESAIAN
\begin{aligned} \displaystyle\lim_{x\to0}\dfrac{x}{\sqrt{5-x}-\sqrt5}&=\displaystyle\lim_{x\to0}\dfrac{x}{\sqrt{5-x}-\sqrt5}{\color{red}\cdot\dfrac{\sqrt{5-x}+\sqrt5}{\sqrt{5-x}+\sqrt5}}\\ &=\displaystyle\lim_{x\to0}\dfrac{x\left(\sqrt{5-x}+\sqrt5\right)}{5-x-5}\\ &=\displaystyle\lim_{x\to0}\dfrac{x\left(\sqrt{5-x}+\sqrt5\right)}{-x}\\ &=\displaystyle\lim_{x\to0}\left(-\sqrt{5-x}-\sqrt5\right)\\ &=-\sqrt{5-0}-\sqrt5\\ &=-\sqrt5-\sqrt5\\ &=\boxed{\boxed{-2\sqrt5}} \end{aligned}
Jadi, \displaystyle\lim_{x\to0}\dfrac{x}{\sqrt{5-x}-\sqrt5}=-2\sqrt5.

No.

\displaystyle\lim_{x\to0}\dfrac{x^3+2x^2}{x^4-x^3+5x^2}=....
ALTERNATIF PENYELESAIAN
\begin{aligned} \displaystyle\lim_{x\to0}\dfrac{x^3+2x^2}{x^4-x^3+5x^2}&=\displaystyle\lim_{x\to0}\dfrac{x^2(x+2)}{x^2\left(x^2-x+5\right)}\\ &=\displaystyle\lim_{x\to0}\dfrac{x+2}{x^2-x+5}\\ &=\dfrac{0+2}{0^2-0+5}\\ &=\boxed{\boxed{\dfrac25}} \end{aligned}
Jadi, \displaystyle\lim_{x\to0}\dfrac{x^3+2x^2}{x^4-x^3+5x^2}=\dfrac25.

No.

\displaystyle\lim_{x\to-3}\dfrac{2x+1}{x^2-3x+4}=....
ALTERNATIF PENYELESAIAN
\begin{aligned} \displaystyle\lim_{x\to-3}\dfrac{2x+1}{x^2-3x+4}&=\dfrac{2(-3)+1}{(-3)^2-3(-3)+4}\\ &=\dfrac{-6+1}{9+9+4}\\ &=\dfrac{-5}{22}\\ &=\boxed{\boxed{-\dfrac5{22}}} \end{aligned}
Jadi, \displaystyle\lim_{x\to-3}\dfrac{2x+1}{x^2-3x+4}=-\dfrac5{22}.

No.

\displaystyle\lim_{x\to0}\dfrac{x^2+3x-1}{x^3+5x}=....
ALTERNATIF PENYELESAIAN
\begin{aligned} \displaystyle\lim_{x\to0}\dfrac{x^2+3x-1}{x^3+5x}&=\dfrac{0^2+3(0)-1}{0^3+5(0)}\\ &=\dfrac{-1}0\\ &=\boxed{\boxed{\infty}} \end{aligned}
Jadi, \displaystyle\lim_{x\to0}\dfrac{x^2+3x-1}{x^3+5x}=\infty.

No.

\displaystyle\lim_{x\to2}\dfrac{x^2-x-2}{x-2}
Dengan menggunakan tabel berikut
Nilai x Nilai y
x = 1,95
x = 1,98
x = 1,99
x = 2,01
x = 2,05
x = 2,1
Berapakah hasil yang kamu peroleh untuk limit fungsi tersebut?
ALTERNATIF PENYELESAIAN
Nilai x Nilai y
x = 1,95 2,95
x = 1,98 2,98
x = 1,99 2,99
x = 2,01 3,01
x = 2,05 3,05
x = 2,1 3,1
Jadi, \displaystyle\lim_{x\to2}\dfrac{x^2-x-2}{x-2}=3.

No.

\displaystyle\lim_{x\to3}x^2+2x+10=....
ALTERNATIF PENYELESAIAN
\begin{aligned} \displaystyle\lim_{x\to3}x^2+2x+10&=3^2+2(3)+10\\ &=9+6+10\\ &=\boxed{\boxed{25}} \end{aligned}
Jadi, \displaystyle\lim_{x\to3}x^2+2x+10=25.


No.

\displaystyle\lim_{x\to2}(3x+2)=....
  1. 4
  2. 5
  3. 6
  1. 7
  2. 8
ALTERNATIF PENYELESAIAN
\begin{aligned} \displaystyle\lim_{x\to2}(3x+2)&=3(2)+2\\ &=6+2\\ &=\boxed{\boxed{8}} \end{aligned}
Jadi, \displaystyle\lim_{x\to2}(3x+2)=8.
JAWAB: E

No.

Tentukan definisi limit berikut apakah limitnya "terdefinisi, tidak terdefinisi, nilai limit \dfrac00"
  1. \displaystyle\lim_{x\to3}\dfrac{x^2-1}{x+1} = ....
  2. \displaystyle\lim_{x\to2}\dfrac{2x^2+1}{2x-4} = ....
  3. \displaystyle\lim_{x\to4}\dfrac{x^2-16}{x-4} = ....
ALTERNATIF PENYELESAIAN

  1. \begin{aligned} \lim_{x\to3}\frac{x^2-1}{x+1}&=\frac{3^2-1}{3+1}\\[3.7pt] &=\frac{9-1}4\\[3.7pt] &=\frac84\\[3.7pt] &=2 \end{aligned} terdefinisi

  2. \begin{aligned} \lim_{x\to2}\frac{2x^2+1}{2x-4}&=\frac{2(2)^2+1}{2(2)-4}\\[3.7pt] &=\frac{2(4)+1}{4-4}\\[3.7pt] &=\frac90 \end{aligned} tidak terdefinisi

  3. \begin{aligned} \lim_{x\to4}\frac{x^2-16}{x-4}&=\frac{4^2-16}{4-4}\\[3.7pt] &=\frac{16-16}0\\[3.7pt] &=\frac00 \end{aligned} nilai limit \dfrac00
Jadi,
  1. terdefinisi
  2. tidak terdefinisi
  3. nilai limit \dfrac00



Post a Comment