If $\sin ( A - B )=\frac{1}{2}, \cos ( A + B )=\frac{1}{2}, 0^{\circ} < A + B \leq 90^{\circ}, A > B ,$ find $A$ and $B$
since, $\sin ( A - B )=\frac{1}{2},$ therefore, $A - B =30^{\circ}$ ......$(1)$
Also, since $\cos ( A + B )=\frac{1}{2},$ therefore, $A + B =60^{\circ}$ ......$(2)$
Solving $(1)$ and $(2),$ we get $: A=45^{\circ}$ and $B=15^{\circ} .$
Evaluate:
$\cos 48^{\circ}-\sin 42^{\circ}$
If $\tan 2 A=\cot \left(A-18^{\circ}\right),$ where $2 A$ is an acute angle, find the value of $A .$ (in $^{\circ}$)
Express the trigonometric ratios $\sin A , \sec A$ and $\tan A$ in terms of $\cot A$.
Evaluate the following:
$\sin 60^{\circ} \cos 30^{\circ}+\sin 30^{\circ} \cos 60^{\circ}$
Given $\sec \theta=\frac{13}{12},$ calculate all other trigonometric ratios.