If the direction cosines <l, m, n> of a line are connected by relation $l + 2m + n = 0, 2l - 2m + 3n = 0$, then what is the value of $l^{2} + m^{2} - n^{2}$?
$\frac{1}{101}$
$\frac{29}{101}$
$\frac{41}{101}$
$\frac{92}{101}$
If a variable line passes through the point of intersection of the lines $x + 2y - 1 = 0$ and $2x - y - 1 = 0$ and meets the coordinate axes in $A$ and $B$, then what is the locus of the mid-point of $AB$?
$3x + y = 10xy$
$x + 3y = 10xy$
$3x + y = 10$
$x + 3y = 10$
What is the equation to the straight line passing through the point $(-sin\theta, cos\theta)$ and perpendicular to the line $xcos\theta + ysin\theta = 9$?
$xsin\theta - ycos\theta - 1 = 0$
$xsin\theta - ycos\theta + 1 = 0$
$xsin\theta - ycos\theta = 0$
$xcos\theta - ysin\theta + 1 = 0$
Two points $P$ and $Q$ lie on line $y = 2x + 3$. These two points $P$ and $Q$ are at a distance 2 units from another point $R(1, 5)$. What are the coordinates of the points $P$ and $Q$?
$(1 + \frac{2}{\sqrt{5}}, 5 + \frac{4}{\sqrt{5}}), (1 - \frac{2}{\sqrt{5}}, 5 - \frac{4}{\sqrt{5}})$
$(3 + \frac{2}{\sqrt{5}}, 5 + \frac{4}{\sqrt{5}}), (-1 - \frac{2}{\sqrt{5}}, 5 - \frac{4}{\sqrt{5}})$
$(1 - \frac{2}{\sqrt{5}}, 5 + \frac{4}{\sqrt{5}}), (1 + \frac{2}{\sqrt{5}}, 5 - \frac{4}{\sqrt{5}})$
$(3 - \frac{2}{\sqrt{5}}, 5 + \frac{4}{\sqrt{5}}), (-1 + \frac{2}{\sqrt{5}}, 5 - \frac{4}{\sqrt{5}})$