$PQ$ is a chord of length $4\ \text{cm}$ of a circle of radius $2.5\ \text{cm}$. The tangents at $P$ and $Q$ intersect at a point $T$. Find the length of $TP$.
Prove that $6\sqrt{3}$ is irrational.
The common difference of the A.P.: $3,\,3+\sqrt{2},\,3+2\sqrt{2},\,3+3\sqrt{2},\,\ldots$ will be:
The discriminant of the quadratic equation $3x^2 - 4\sqrt{3}\,x + 4 = 0$ will be:
The number of solutions of the pair of linear equations $\tfrac{4}{3}x + 2y = 8$, $2x + 3y = 12$ will be:
In the figure $DE \parallel BC$. If $AD = 3\,\text{cm}$, $DE = 4\,\text{cm}$ and $DB = 1.5\,\text{cm}$, then the measure of $BC$ will be: