English

Given that P(3, 2, –4), Q(5, 4, –6) and R(9, 8, –10) Are Collinear. Find the Ratio in Which Qdivides Pr. - Mathematics

Advertisements
Advertisements

Question

Given that  P(3, 2, –4), Q(5, 4, –6) and R(9, 8, –10) are collinear. Find the ratio in which Qdivides PR

Solution

Let Q divide PR in the ratio \[\lambda\] Thus, the coordinates of Q are as follows: 

\[\left( \frac{9\lambda + 3}{\lambda + 1}, \frac{8\lambda + 2}{\lambda + 1}, \frac{- 10\lambda - 4}{\lambda + 1} \right)\] 

But, the coordinates of Q are (5, 4, −6) .

\[\left( \frac{9\lambda + 3}{\lambda + 1}, \frac{8\lambda + 2}{\lambda + 1}, \frac{- 10\lambda - 4}{\lambda + 1} \right)\]

These three equation gives \[\lambda = \frac{1}{2}\] So, Q divides PR in the ratio\[\frac{1}{2}: 1\]

shaalaa.com
  Is there an error in this question or solution?
Chapter 28: Introduction to three dimensional coordinate geometry - Exercise 28.3 [Page 20]

APPEARS IN

RD Sharma Mathematics [English] Class 11
Chapter 28 Introduction to three dimensional coordinate geometry
Exercise 28.3 | Q 15 | Page 20

Video TutorialsVIEW ALL [1]

RELATED QUESTIONS

A point is on the x-axis. What are its y-coordinates and z-coordinates?


The coordinates of points in the XY-plane are of the form _______.


Find the coordinates of a point on y-axis which are at a distance of `5sqrt2` from the point P (3, –2, 5).


A point R with x-coordinate 4 lies on the line segment joining the pointsP (2, –3, 4) and Q (8, 0, 10). Find the coordinates of the point R.

[Hint suppose R divides PQ in the ratio k: 1. The coordinates of the point R are given by `((8k + 2)/(k+1), (-3)/(k+1), (10k + 4)/(k+1))`


If A and B be the points (3, 4, 5) and (–1, 3, –7), respectively, find the equation of the set of points P such that PA2 + PB2 = k2, where k is a constant.


The mid-points of the sides of a triangle ABC are given by (–2, 3, 5), (4, –1, 7) and (6, 5, 3). Find the coordinates of AB and C.


A(1, 2, 3), B(0, 4, 1), C(–1, –1, –3) are the vertices of a triangle ABC. Find the point in which the bisector of the angle ∠BAC meets BC.


Find the coordinates of the points which tisect the line segment joining the points P(4, 2, –6) and Q(10, –16, 6). 


Using section formula, show that he points A(2, –3, 4), B(–1, 2, 1) and C(0, 1/3, 2) are collinear.

 


Find the ratio in which the line segment joining the points (4, 8, 10) and (6, 10, –8) is divided by the yz-plane. 


Find the coordinates of a point equidistant from the origin and points A (a, 0, 0), B (0, b, 0) andC(0, 0, c). 


Write the coordinates of the point P which is five-sixth of the way from A(−2, 0, 6) to B(10, −6, −12). 


Determine the point on yz-plane which is equidistant from points A(2, 0, 3), B(0, 3,2) and C(0, 0,1).


If the origin is the centroid of a triangle ABC having vertices A(a, 1, 3), B(−2, b −5) and C (4, 7, c), find the values of a, b, c.


P is a point on the line segment joining the points (3, 2, –1) and (6, 2, –2). If x co-ordinate of P is 5, then its y co-ordinate is ______.


The equations of x-axis in space are ______.


The points (1, 2, 3), (–2, 3, 4) and (7, 0, 1) are collinear.


The vector equation of the line passing through the points (3, 5, 4) and (5, 8, 11) is.


Find the position vector of a point A in space such that `vec(OA)` is inclined at 60º to OX and at 45° to OY and `|vec(OA)|` = 10 units


Find the vector equation of the line which is parallel to the vector `3hati - 2hatj + 6hatk` and which passes through the point (1 ,–2, 3).


Show that the lines `(x - 1)/2 = (y - 2)/3 = (z - 3)/4` and `(x - 4)/5 = (y - 1)/2` = z intersect.. Also, find their point of intersection.


The reflection of the point (α, β, γ) in the xy-plane is ______.


A plane passes through the points (2, 0, 0) (0, 3, 0) and (0, 0, 4). The equation of plane is ______.


The equation of a line, which is parallel to `2hati + hatj + 3hatk` and which passes through the point (5, –2, 4), is `(x - 5)/2 = (y + 2)/(-1) = (z - 4)/3`.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×