Showing posts with label are parallel or coincident. Show all posts
Showing posts with label are parallel or coincident. Show all posts

Sunday, March 31, 2013

On comparing the ratios a1/a2 , b1/b2 and c1/c2, find out whether the lines representing the following pairs of linear equations intersect at a point, are parallel or coincident

On comparing the ratios a1/a2 , b1/b2  and c1/c2, find out whether the lines representing the following pairs of linear equations intersect at a point, are parallel or coincident
Use this table for the solution
S.N.
Compare the Ratio
Graphic representation
Algebraic interpretation
Linear equations
1
 
Intersection lines at one point
Exactly one solution or
unique solution
Consistent

2
 
Coincident line
Infinity solution or many solutions
 Dependent and consistent
3
Parallel lines
No solution
Inconsistent


(i)                      5x – 4y + 8         = 0
7x + 6y – 9         = 0
Compare the equation with
                          
We get
a1 = 5,            b1       = -4,               and c1 = 8
a2 =7               b2       =6                    and c2 = -9
Hence
 
So both are Intersecting lines at one point
(ii)          9x + 3y + 12            = 0
18x + 6y + 24           = 0
Compare the equation with
               
We get
a1 = 9,           b1       = 3,                 and c1 = 12
a2 =18          b2        =6,                   and c2 = 24
 
Hence
So both lines are coincident
(ii)            6x – 3y + 10       = 0
2x y + 9            = 0
Compare the equation with
                          
We get
a1 = 6,            b1       =- 3,               and c1 = 10
a2 =2              b2        =-1,                 and c2 = 9 
 
Hence 
So both lines are parallel