The smallest positive integral value of n such that $${\left[ {{{1 + \sin {\pi \over 8} + i\cos {\pi \over 8}} \over {1 + \sin {\pi \over 8} - i\cos {\pi \over 8}}}} \right]^n}$$ is purely imaginary, is equal to
Given that a house forms a right angle view from a window of another house, and the angle of elevation from the base of the first house to the window is 60 degrees. If the separation between the two houses is 6 meters, calculate the height of the first house.
A spherical balloon is filled with 4500$$\pi$$ cubic meters of helium gas. If a leak in the balloon causes the gas to escape at the rate of 72$$\pi$$ cubic meters per minute then the rate (in meters per minute) at which the radius of the balloon decreases 49 min after the leakage began is
If in a $$\Delta$$ABC, 2b2 = a2 + c2, then $$\frac{\sin 3B}{\sin B}$$ is equal to