48 views
$1)$What is the value of $\sin 15^{o}$

$\sin 15^{o}=\sin \left ( 60^{o}-45^{o} \right )$

$=\sin 60^{o}.\cos 45^{o}-\cos 60^{o}.\sin 45^{o}$

$=\left ( \frac{\sqrt{3}}{2} \right ).\left ( \frac{1}{\sqrt{2}} \right )-\left ( \frac{1}{2} \right ).\left ( \frac{1}{\sqrt{2}} \right )$

$=\frac{\sqrt{3}-1}{2\sqrt{2}}$
$=\frac{\sqrt{3}-1}{2\sqrt{2}}=0.258$
Is it correct?

$2)$ $\sin 80^{o}$ value=_____________

Is it possible to do?
| 48 views
+1

Do you know any two numbers for which you know their sin values and adding/subtracting them gives 80?

0
But $\sin18^{o}$ value possible. rt??
0

1
2