Straight Lines

Let the distance between two parallel lines be 5 units and a point P lie between the lines at a unit distance from one of them. An equilateral triangle PQR is formed such that Q lies on one of the parallel lines, while R lies on the other. Then (QR)2 is equal to .

A variable line L passes through the point (3, 5) and intersects the positive coordinate axes at the points A and B. The minimum area of the triangle OAB, where O is the origin, is :

1. 35
2. 25
3. 30
4. 40

A ray of light coming from the point P(1, 2) gets reflected from the point Q on the x-axis and then passes through the point R(4, 3). If the point S(h, k) is such that PQRS is a parallelogram, then hk2 is equal to:

1. 60
2. 70
3. 80
4. 90

Two vertices of a triangle ABC are A(3, -1) and B(-2, 3), and its orthocentre is P(1, 1). If the coordinates of the point C are ( , ) and the centre of the circle circumscribing the triangle PAB is (h, k), then the value of ( + ) + 2(h + k) equals

1. 81
2. 15
3. 51
4. 5

The equations of two sides AB and AC of a triangle ABC are 4x + y = 14 and 3x - 2y = 5, respectively. The point (2, - 43 ) divides the third side BC internally in the ratio 2 : 1, the equation of the side BC is

1. x + 6y + 6 = 0
2. x - 3y - 6 = 0
3. x + 3y + 2 = 0
4. x - 6y - 10 = 0

If the orthocentre of the triangle formed by the lines 2x + 3y - 1 = 0, x + 2y - 1 = 0 and ax + by - 1 = 0, is the centroid of another triangle, whose circumcentre and orthocentre respectively are (3, 4) and (-6, -8), then the value of |a - b| is .

If the line segment joining the points (5, 2) and (2, a) subtends an angle 4 at the origin, then the absolute value of the product of all possible values of a is :

1. 4
2. 8
3. 6
4. 2

If the image of the point (-4, 5) in the line x + 2y = 2 lies on the circle (x + 4)2 + (y - 3)2 = r2, then r is equal to:

1. 2
2. 3
3. 4
4. 1

Let a ray of light passing through the point (3, 10) reflects on the line 2x + y = 6 and the reflected ray passes through the point (7, 2). If the equation of the incident ray is ax + by + 1 = 0, then a2 + b2 + 3ab is equal to .

Let a variable line of slope m > 0 passing through the point (4, -9) intersect the coordinate axes at the points A and B. The minimum value of the sum of the distances of A and B from the origin is

1. 30
2. 15
3. 10
4. 25