State whether the following are true or false. Justify your answer.
The value of $\cos \theta$ increases as $\theta$ increases
$\cos 0^{\circ}=1$
$\cos 30^{\circ}=\frac{\sqrt{3}}{2}=0.866$
$\cos 45^{\circ}=\frac{1}{\sqrt{2}}=0.707$
$\cos 60^{\circ}=\frac{1}{2}=0.5$
$\cos 90^{\circ}=0$
It can be observed that the value of $\cos \theta$ does not increase in the interval of$0^{\circ}<\theta<90^{\circ}$
Hence, the given statement is false.
In $\triangle PQR ,$ right $-$ angled at $Q , PR + QR =25\, cm$ and $PQ =5\, cm .$ Determine the values of $\sin P, \cos P$ and $\tan P$.
In $Fig.$ find $\tan P-\cot R .$
Prove that $\frac{\cot A-\cos A}{\cot A+\cos A}=\frac{\operatorname{cosec} A-1}{\operatorname{cosec} A+1}$
$\sin 2 A=2 \sin A$ is true when $A=$
If $A , B$ and $C$ are interior angles of a triangle $ABC ,$ then show that
$\sin \left(\frac{B+C}{2}\right)=\cos \frac{A}{2}$