Question:
Find the value of x in each of the following :
$\tan x=\sin 45^{\circ} \cos 45^{\circ}+\sin 30^{\circ}$
Solution:
We have,
$\tan x=\sin 45^{\circ} \cos 45^{\circ}+\sin 30^{\circ} \ldots \ldots$ (1)
Now we know that
$\sin 45^{\circ}=\cos 45^{\circ}=\frac{1}{\sqrt{2}}$ and $\sin 30^{\circ}=\frac{1}{2}$
Now by substituting above values in equation (1), we get,
$\tan x=\sin 45^{\circ} \cos 45^{\circ}+\sin 30^{\circ}$
$\tan x=\frac{1}{\sqrt{2}} \times \frac{1}{\sqrt{2}}+\frac{1}{2}$
$=\frac{1}{\sqrt{2} \times \sqrt{2}}+\frac{1}{2}$
$=\frac{1}{2}+\frac{1}{2}$
$=\frac{1+1}{2}$
$=\frac{2}{2}$
$=1$
Therefore,
$\tan x=1 \ldots \ldots$ (2)
Since,
$\tan 45^{\circ}=1 \ldots \ldots(3)$
Therefore by comparing equation (2) and (3)
We get,
$x=45^{\circ}$
Therefore,
$x=45^{\circ}$