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 $B=15^{\circ} .$
State whether the following are true or false. Justify your answer.
The value of $\sin \theta$ increases as $\theta$ increases.
In $\triangle PQR ,$ right $-$ angled at $Q , PR + QR =25\, cm$ and $PQ =5\, cm .$ Determine the values of $\sin P, \cos P$ and $\tan P$.
Given $15 \cot A =8,$ find $\sin A$ and $\sec A .$
If $\angle A$ and $\angle B$ are acute angles such that $\cos A =\cos B ,$ then show that $\angle A =\angle B$.
Evaluate:
$\operatorname{cosec} 31^{\circ}-\sec 59^{\circ}$