If $\sin \theta + \cos \theta = 1$, then $\sin \theta \cos \theta = $
$0$
$1$
$2$
$0.5$
If in two circles, arcs of the same length subtend angles $60^{\circ}$ and $75^{\circ}$ at the centre, find the ratio of their radii.
The angle subtended at the centre of a circle of radius $3$ metres by an arc of length $1$ metre is equal to
Find the value of $\sin 15^{\circ}$
Prove that: $(\sin 3 x+\sin x) \sin x+(\cos 3 x-\cos x) \cos x=0$
Find the value of the trigonometric function $\cot \left(-\frac{15 \pi}{4}\right)$