$2\sin A{\cos ^3}A - 2{\sin ^3}A\cos A = $

The value of $\cos 41^{\circ} \cdot \cos 42^{\circ} \cdot \cos 43^{\circ} \cdot \cos 44^{\circ} \cdot \cos 45^{\circ} \cdot \cos 46^{\circ} \cdot \cos 47^{\circ} \cdot \cos 48^{\circ} \cdot \cos 49^{\circ}$ is:

If $\frac{\pi}{2} < \alpha < \pi$ and $\pi < \beta < \frac{3\pi}{2}$,with $\sin \alpha = \frac{15}{17}$ and $\tan \beta = \frac{12}{5}$,then the value of $\sin(\beta - \alpha)$ is: (in $/221$)

Which of the following is true?

$\cos^2 A(3 - 4\cos^2 A)^2 + \sin^2 A(3 - 4\sin^2 A)^2 = $

$A$ tree breaks at a certain height and the upper part touches the ground,making an angle of $60^{\circ}$ with the ground at a distance of $10 \text{ m}$ from its foot. The original height of the tree was (in $\text{m}$):