Q57 / 120 · VITEEE 2011 · Mathematics
Find the value of $(7.995)^{1 / 3}$ correct to four decimal places.
- A$1.9995$
- Correct answerB$1.9996$
- C$1.9990$
- D$1.9991$
Solution
$$
\begin{array}{l}
(7.995)^{1 / 3}=(8-0.005)^{1 / 3} \\
=2\left(1-\frac{0.005}{8}\right)^{1 / 3} \\
=2\left[1+\left(\frac{1}{3}\right)\left(-\frac{0.005}{8}\right)\right]=2[1-0.000208] \\
=1.9996
\end{array}
$$
Hence, the correct answer is option: 'B'.