- Data Structure
- Networking
- RDBMS
- Operating System
- Java
- MS Excel
- iOS
- HTML
- CSS
- Android
- Python
- C Programming
- C++
- C#
- MongoDB
- MySQL
- Javascript
- PHP
- Physics
- Chemistry
- Biology
- Mathematics
- English
- Economics
- Psychology
- Social Studies
- Fashion Studies
- Legal Studies
- Selected Reading
- UPSC IAS Exams Notes
- Developer's Best Practices
- Questions and Answers
- Effective Resume Writing
- HR Interview Questions
- Computer Glossary
- Who is Who
Find the cube root of each of the following rational numbers:
(i) $0.001728$
(ii) $0.003375$
(iii) $0.001$
(iv) $1.331$
To find:
We have to find the cube root of the given rational numbers.
Solution:
(i) $\sqrt[3]{0.001728}=\sqrt[3]{\frac{1728}{1000000}}$
$=\frac{\sqrt[3]{1728}}{\sqrt[3]{1000000}}$
$=\frac{\sqrt[3]{2 \times 2 \times 2 \times 2 \times 2 \times 2 \times 3 \times 3 \times 3}}{\sqrt[3]{10 \times 10 \times 10 \times 10 \times 10 \times 10}}$
$=\frac{\sqrt[3]{2^{3} \times 2^{3} \times 3^{3}}}{\sqrt[3]{10^{3} \times 10^{3}}}$
$=\frac{2 \times 2 \times 3}{10 \times 10}$
$=\frac{12}{100}$
$=0.12$
(ii) $\sqrt[3]{0.003375}=\sqrt[3]{\frac{3375}{1000000}}$
$=\frac{\sqrt[3]{3375}}{\sqrt[3]{1000000}}$
$=\frac{\sqrt[3]{3 \times 3 \times 3 \times 5 \times 5 \times 5}}{\sqrt[3]{10 \times 10 \times 10 \times 10 \times 10 \times 10}}$
$=\frac{\sqrt[3]{3^{3} \times 5^{3}}}{\sqrt[3]{10^{3} \times 10^{3}}}$
$=\frac{3 \times 5}{10 \times 10}$
$=\frac{15}{100}$
$=0.15$
(iii) $\sqrt[3]{0.001}=\sqrt[3]{\frac{1}{1000}}$
$=\frac{\sqrt[3]{1}}{\sqrt[3]{1000}}$
$=\frac{\sqrt[3]{1 \times 1 \times 1}}{\sqrt[3]{10 \times 10 \times 10}}$
$=\frac{1}{\sqrt[3]{10^{3}}}$
$=\frac{1}{10}$
$=0.1$
(iv) $\sqrt[3]{1.331}=\sqrt[3]{\frac{1331}{1000}}$
$=\frac{\sqrt[3]{1331}}{\sqrt[3]{1000}}$
$=\frac{\sqrt[3]{11 \times 11 \times 11}}{\sqrt[3]{10 \times 10 \times 10}}$
$=\frac{\sqrt[3]{11^{3}}}{\sqrt[3]{10^{3}}}$
$=\frac{11}{10}$
$=1.1$