logo

Ask Questions, Get Answers

 
X
 Search
Want to ask us a question? Click here
Browse Questions
Ad
Home  >>  CBSE XI  >>  Math  >>  Trigonometric Functions
0 votes

The value of $\sin 50^{\large\circ}-\sin 70^{\large\circ}+\sin 10^{\large\circ}$ is

$\begin{array}{1 1}(A)\;1&(B)\;0\\(C)\;\large\frac{1}{2}&(D)\;2\end{array} $

Can you answer this question?
 
 

1 Answer

0 votes
Toolbox:
  • $\sin A-\sin B=2\cos \large\frac{A+B}{2}$$.\sin \large\frac{A-B}{2}$
$\sin 50^{\large\circ}-\sin 70^{\large\circ}+\sin 10^{\large\circ}$
$2\cos \large\frac{50^{\large\circ}+70^{\large\circ}}{2}$$.\sin \large\frac{50^{\large\circ}-70^{\large\circ}}{2}$$+\sin 10^{\large\circ}$
$2\cos 60^{\large\circ}\sin(-10)^{\large\circ}+\sin 10^{\large\circ}$
$-\sin 10^{\large\circ}+\sin 10^{\large\circ}=0$
Hence (B) is the correct answer.
answered Apr 21, 2014 by sreemathi.v
 
Ask Question
student study plans
x
JEE MAIN, CBSE, NEET Mobile and Tablet App
The ultimate mobile app to help you crack your examinations
Get the Android App
...