The number of points of intersection of two curves y = 2 sin x and y $$ = 5{x^2} + 2x + 3$$ is

If p, q, r are + ve and are on A.P., the roots of quadratic equation $$p{x^2} + qx + r = 0$$ are all real for

Let $$p,q \in \left\{ {1,2,3,4} \right\}\,$$. The number of equations of the form $$p{x^2} + qx + 1 = 0$$ having real roots is

Let $$n$$ be positive integer. If the coefficients of 2nd, 3rd, and 4th terms in the expansion of $${\left( {1 + x} \right)^n}$$ are in A.P., then the value of $$n$$ is ................