CBSE Class 10 Answered
Question 3
Prove that the points (a,0), (b,0) and (1,1) are collinear if 1/a+1/b=1.
Asked by | 28 Feb, 2013, 10:32: AM
Expert Answer
Sometimes there can be printing mistakes in the book of sample papers also. If you will try to solve it using the section method and try to find the ratio, you will find that the ratio would come out to be 0 if you consider the points that you provided, which is not possible for collinear points. So, yeah, there can be mistakes everywhere. Sometimes NCERT books (even Board exam papers) also have mistakes, so, its alright.
If the question as I said would have been "Prove that the points (a,0), (0,b) and (1,1) are collinear if 1/a+1/b=1.", then you can solve it as
Let A(a,0), B(0,b) and C(1,1) be the 3 collinear points
Let B divide the line segment joining AC in the ratio of k:1
Then, by section formula, the coordinates of B would be given by (k+a/k+1 , k/k+1)
However, we already know that the coordinates of B is (0,b)
So, equating, 0 = k+a/k+1 i.e. k = -a
Also, b = k/k+1
Substituting k = -a, we get
b = -a/-a+1
i.e. 1/b = a-1/a
i.e. 1/b = 1-1/a
i.e. 1/a+1/b = 1
Hence, proved
Answered by | 28 Feb, 2013, 06:35: PM
Application Videos
-
Collinear Points
This video explains the concept of Collinear Points and Area of a Triangle. -
Distance Formula
This video explains the concept of Distance Formula to find the distance be... -
Mid - Point Formula
This video explains the concept Parallelogram, Mid-Point Formula, Property ... -
Distance Between two Given Points
The video explains to find distance between two points using distance fo...
-
Internal Section Formula
The video explains section formula when a point internally divides a lin...
Concept Videos
-
Distance Formula
This video explains distance formula, its theory and application. -
Section Formula
Use section formula to find mid point of a line segment whose end points a... -
Finding area of a triangles using coordinate method ...
This video explains ways of finding area of a triangle using coordinate geo... -
Applications of Section Formula
Applications of Section Formula -
Distance Formula
This video explains distance formula, its theory and application.
CBSE 10 - Maths
Asked by pathakvaishnavi9139 | 23 Mar, 2024, 10:45: AM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by jdharmendra097 | 21 Feb, 2024, 08:02: PM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by raj.mehta2006 | 21 Feb, 2024, 11:23: AM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by lakshmidasari280 | 29 Jan, 2024, 07:44: PM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by namansinghnamansinghdelhi | 22 Dec, 2023, 10:44: PM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by kavitayadav9001419917 | 23 Nov, 2023, 08:14: PM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by sufibadole08 | 19 Nov, 2023, 09:13: AM
ANSWERED BY EXPERTCBSE 10 - Maths
Asked by kadaramyadav | 02 Nov, 2023, 11:02: PM
ANSWERED BY EXPERT
