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 [2024]
10
25
30
15
(2)
Equation of line passing through (4, –9) and having slope m is given by
(y + 9) = m(x – 4)
Since it intersect the coordinate axes at points A and B so at A, y = 0
Similarly at B, x = 0
Now, let O(0, 0) be origin, then
Now,
If the locus of the point, whose distance from the point (2, 1) and (1, 3) are in the ratio 5 : 4, is , then the value of is equal to : [2024]
5
– 27
37
437
(3)
Let given point be (h, k) whose distance from (2, 1) and (1, 3) is in ratio 5 : 4.
On replacing h by x and k by y, we get
On comparing, we get
If the line segment joining the points (5, 2) and (2, a) subtends an angle at the origin, then the absolute value of the product of all possible values of a is: [2024]
8
2
4
6
(3)
Angle between the lines is
Since,
Required product .
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 is equal to: [2024]
70
90
60
80
(1)
Slope of
Equation of
Since, point Q is on x-axis.
Let
Also, point Q lies P'R
Now, PQRS is a parallelogram
and
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 equals [2024]
15
5
51
81
(2)
Slope of
Slope of
Equation of PC is given
4y – 4 = 5x – 5
5x – 4y – 1 = 0 ... (i)
Now slope of
Slope of BC = 1
Equation of BC is given by
y – 3 = 1(x + 2)
x – y + 5 = 0 ... (ii)
Solving (i) and (ii), we get
and
Centre of circle circumseribing is point of intersection of perpendicular bisector of AP, AB and AC.
Equation of perpendicular bisector of AP
y – 0 = x – 2
y = x – 2 ... (iii)
Equation of perpendicular bisector of AB
... (iv)
On solving (iii) and (iv), we get
So, .
Let and let and D(1, 2) be the vertices of a parallelogram ABCD. If and the points A and C lie on the line 3y = 2x + 1, then is equal to [2024]
12
10
8
5
(3)
Givem, and D(1, 2).
Using mid point Formula.
So,
.
Let and be the vertices of a parallelogram ABCD. If the point C lies on 2x – y = 5 and the point D lies on 3x – 2y = 6, then the value of is equal to __________. [2024]
(32)
We have, A(–2, –1), B(1, 0), and be the vertices of a parallelogram ABCD.
Since, lies on 2x – y = 5
... (i)
Also, lies on the line 3x – 2y = 6
So, ... (ii)
Now,
... (iii)
From (ii),
Solving (i) and (iii), we get
.
Let the three sides of a triangle are on the lines 4x – 7y + 10 = 0, x + y = 5 and 7x + 4y = 15. Then the distance of its orthocentre from the orthocentre of the triangle formed by the lines x = 0, y = 0 and x + y = 1 is [2025]
20
5
1
Since the lines 4x –7y + 10 = 0 and 7x + 4y = 15 are perpendicular to each other.
So, the triangle formed by lines 4x –7y + 10 = 0, 7x + 4y = 15 and x + y = 5 is right angled triangle.
So, orthrocentre = Point of intersection of 4x – 7y + 10 = 0 and 7x + 4y = 15 which is, B = (1, 2)
Also, triangle formed by sides x = 0, y = 0, x + y = 1 is right angled triangle.
So, orthrocentre, Q = (0, 0)
Distance between Q and .
Let the area of a PQR with vertices P(5, 4), Q(–2, 4) and R(a, b) be 25 square units. If its orthocenter and centroid are and C(c, d) respectively, then c + 2d is equal to [2025]
2
3
(2)
Since,
... (i)
Also,
... (ii)
Solving equations (i) and (ii), we get
a = 2, b = 6
Now, centroid of PQR = (c, d)
.
Let the points lie on or inside the triangle with sides x + y = 11, x + 2y = 16 and 2x + 3y = 29. Then the product of the smallest and the largest values of is equal to : [2025]
22
55
33
44
(3)
Given that a triangle bounded by lines : x + y = 11, : x + 2y =16 and : 2x + 3y = 29.
The region is given by
Using : When , y = 11 – x
(minimum)
Using : when x = 11/2, 3y = 29 – 2x
(maximum)
Product of the smallest and the largest value of .