If $\tan ( A + B )=\sqrt{3}$ and $\tan ( A - B )=\frac{1}{\sqrt{3}} ; 0^{\circ}< A + B \leq 90^{\circ} ; A > B ,$ find $A$ and $B$
$\tan (A+B)=\sqrt{3}$
$\Rightarrow \tan (A+B)=\tan 60$
$\Rightarrow A+B=60 \ldots(1)$
$\tan ( A - B )=\frac{1}{\sqrt{3}}$
$\Rightarrow \tan (A-B)=\tan 30$
$\Rightarrow A-B=30 \ldots(2)$
On adding both equations, we obtain
$2 A =90$
$\Rightarrow A=45$
From equation $(1),$ we obtain
$45+B=60$
$B=15$
Therefore, $\angle A =45^{\circ}$ and $\angle B =15^{\circ}$
Show that:
$(i)$ $\tan 48^{\circ} \tan 23^{\circ} \tan 42^{\circ} \tan 67^{\circ}=1$
$(ii)$ $\cos 38^{\circ} \cos 52^{\circ}-\sin 38^{\circ} \sin 52^{\circ}=0$
In $\triangle ABC ,$ right-angled at $B , AB =24 \,cm , BC =7 \,cm .$ Determine:
$(i)$ $\sin A, \cos A$
$(ii)$ $\sin C, \cos C$
$\frac{2 \tan 30^{\circ}}{1-\tan ^{2} 30^{\circ}}=$
If $\sec 4 A =\operatorname{cosec}\left( A -20^{\circ}\right),$ where $4 A$ is an acute angle, find the value of $A$. (in $^{\circ}$)
If $\tan 2 A=\cot \left(A-18^{\circ}\right),$ where $2 A$ is an acute angle, find the value of $A .$ (in $^{\circ}$)