The equation $$(\cos \beta - 1){x^2} + (\cos \beta )x + \sin \beta = 0$$ in the variable x has real roots, then $$\beta$$ lies in the interval
An ordered pair ($$\alpha$$, $$\beta$$) for which the system of linear $$(1 + \alpha )x + \beta y + z = 2$$, $$\alpha x + (1 + \beta )y + z = 3$$, $$\alpha x + \beta y + 2z = 2$$ has a unique solution.
A bird is sitting on the top of a vertical pole 20 m high and its elevation from a point O on the ground is 45$$^\circ$$. If flies off horizontally straight way from the point O. After one second, the elevation of the bird from O is reduced to 30$$^\circ$$, then the speed (in m/s) of the bird is
If one GM, g and two AM's p and q are inserted between two numbers a and b, then (2p $$-$$ q) (p $$-$$ 2q) is equal to