- 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
Prove that: $\frac{sin\theta}{cot\theta+cosec\theta}=2+\frac{sin\theta}{cot\theta-cosec\theta}$.
Given: $\frac{sin\theta}{cot\theta+cosec\theta}=2+\frac{sin\theta}{cot\theta-cosec\theta}$.
To do: To prove $L.H.S.=R.H.S.$
Solution:
$L.H.S. =\frac{sin\theta}{cot\theta+cosec\theta}$
$= \frac{sin\theta}{\frac{cos\theta}{sin\theta}+\frac{1}{sin\theta}}$
$= \frac{sin\theta}{\frac{cos\theta+1}{sin\theta}}$
$= \frac{sin^{2}\theta}{(1+cos\theta)}$
$= \frac{(1-cos^{2}\theta)}{(1+cos\theta)}$ $\because sin^{2}\theta = 1 - cos^{2}\theta$
$= \frac{[( 1+cos\theta)( 1-cos\theta)]}{( 1+cos\theta)}$ $\because a^{2}-b^{2} = ( a+b)( a-b)$
$= 1 - cos\theta ......( 1)$
$R.H.S. = 2+ \frac{sin\theta}{(cot\theta-cosec\theta)}$
$= 2+\frac{sin\theta}{\frac{cos\theta}{sin\theta}-\frac{1}{sin\theta}}$
$= 2+\frac{sin\theta}{\frac{cos\theta-1}{sin\theta}}$
$= 2+ \frac{[ sin^{2}\theta}{(cos\theta-1)]}$
$= 2 - \frac{( sin^{2}\theta)}{( 1-cos\theta)}$
$= 2- \frac{[ ( 1-cos^{2}\theta)}{( 1-cos\theta)]}$
$= 2-\frac{[( 1+cos\theta)( 1-cos\theta)}{( 1-cos\theta)]}$
$= 2 - ( 1+cos\theta)$
$= 2-1-cos\theta$
$= 1-cos\theta ......(2)$
Form $( 1)$ & $( 2)$ , we conclude that,
$( 1) = ( 2)$
$L.H.S. = R.H.S.$
Advertisements