Question
Evaluate the following limits: $\lim _{y \rightarrow 1}\left[\frac{2 y-2}{\sqrt[3]{7+y}-2}\right]$

Answer

$\lim _{y \rightarrow 1} \frac{2 y-2}{\sqrt[3]{7+y}-2}$
$=\lim _{y \rightarrow 1} \frac{2(y-1)}{(7+y)^{\frac{1}{3}}-8^{\frac{1}{3}}} \cdots\left[\because 2=\left(2^3\right)^{\frac{1}{3}}=8^{\frac{1}{3}}\right]$
$=\lim _{y \rightarrow 1} \frac{2}{\frac{(y+7)^{\frac{1}{3}}-8^{\frac{1}{3}}}{y-1}}$
$=\frac{\lim _{y \rightarrow 1} 2}{\lim _{y \rightarrow 1} \frac{(y+7)^{\frac{1}{3}}-8^{\frac{1}{3}}}{(y+7)-8}}$
$=\frac{2}{\frac{1}{3}(8)^{\frac{-2}{3}}} \quad \ldots\left[\begin{array}{l} \because y \rightarrow 1, y+7 \rightarrow 8 \\
\text { and } \lim _{x \rightarrow a} \frac{x^n-\mathrm{a}^n}{x-\mathrm{a}}=\mathrm{n} \cdot \mathrm{a}^{\mathrm{n}-1}
\end{array}\right]$
$=2(3) \cdot(8)^{\frac{2}{3}}$
$=6\left(2^3\right)^{\frac{2}{3}}$
$=6 \times(2)^2$
$=24$
 

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

Evaluate the following limits:
$\lim _{x \rightarrow 0}\left(\frac{3}{x \sqrt{9-x}}-\frac{1}{x}\right)$
Is $68$ a them of the A.P. $7, 10, 13, ...?$
In a class of 200 students who appeared in certain examinations, 35 students faded in CET, 40 in NEET and 40 in JEE, 20 faded in CET and NEET, 17 in NEET and JEE, 15 in CET and JEE and 5 faded in ad three examinations. Find how many students (i) did not fail in any examination. 2. faded in NEET or JEE entrance.
If $\sin\text{x}=\frac{3}{5},\tan\text{y}=\frac{1}{2}$ and $\frac{\pi}{2}<\text{x}<\pi<\text{y}<\frac{3\pi}{2},$ find the value of $8\tan\text{x}-\sqrt{5}\sec\text{y}.$
The length of the perpendicular from the origin to a line is 7 and the line makes an angle of 150° with the positive direction of Y-axis. Find the equation of the line.
The first term of an A.P. is $2$ and the last term is $50.$ The sum of all these terms is $442$. Find the common difference.
A company manufactures cassettes and its cost and revenue functions for a week are $\text{C}=300+\frac{3}{2}\text{x}$ R = 2x respectively, where x is the number of cassettes produced and sold in a week. How many cassettes must be sold for the company to realize a profit?
Evaluate the following limit:
$\lim\limits_{\text{x}\rightarrow{1}}\frac{\text{x}^{15}-1}{\text{x}^{10}-1}$
The function f is defined by $\text{f(x)}=\begin{cases}\text{x}^2,& 0\leq\text{x}\leq3\\3\text{x},&3\leq\text{x}\leq10\end{cases}$
The relation g is defined by $\text{g(x)}=\begin{cases}\text{x}^2,& 0\leq\text{x}\leq2\\3\text{x},&2\leq\text{x}\leq10\end{cases}$
Show that f is a function and g is not a function.
In how many ways can a team of 3 boys and 3 girls be selected from 5 boys and 4 girls?