The lines i beg your pardon coincide or lie on peak of each other are referred to as coincident lines. You may have learned about different varieties of currently in Geometry, such together parallel lines, perpendicular lines, with respect to a two-dimensional or three-dimensional plane.

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In the situation of parallel lines, they room parallel to every other and have a defined distance in between them. Top top the other hand, perpendicular lines room lines which crossing each other at 90 degrees. But, both parallel lines and perpendicular lines carry out not coincide with each other.


Apart from these 3 lines, there are many lines which are neither parallel, perpendicular, nor coinciding. They might be oblique present or intersecting lines, which crossing at various angles, rather of perpendicular to each other.

Coincident currently Definition

The indigenous ‘coincide’ way that it occurs at the exact same time. In regards to Maths, the coincident lines room lines that lie top top each various other in such a method that when we look in ~ them, they show up to be a solitary line, rather of double or many lines.

If we watch in the number of coincident lines, it appears as a single line, but in actual us have attracted two present here. First, we drew a heat of violet color and then on optimal of it drew another line of black color color.


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Coincident lines Equation

When we think about the equation that a line, the standard type is:

y = mx + b

Where m is the steep of the line and also b is the intercept.

Equation that Parallel Lines:

Now, in the instance of 2 lines which space parallel to each other, we stand for the equations of the lines as:

y = m1x + b1

And y = m2x + b2

For example, y = 2x + 2 and y = 2x + 4 space parallel lines. Here, the slope is equal to 2 because that both the lines and also the intercept difference between them is 2. Hence, they are parallel in ~ a street of 2 units.

Equation of Coincident Lines:

When us speak around coincident lines, the equation for lines is given by;

ax + by = c

When two lines are coinciding to each other, then there might be no intercept difference between them.

For example, x + y = 2 and also 2x + 2y = 4 room coinciding lines. The 2nd line is twice the first line.

Because if we placed ‘y’ on the Left-hand side and also the remainder of the equation on the Right-hand side, then us get;

First Line: y = 2 – x …… (1)

Second line: 2y = 4 – 2x

2y = 2(2 – x)

y = 2 – x ………………….(2)

From equation (1) and also (2),

Both the lines are the same.

Hence, they coincide.

Coincident lines Formula

Suppose a1x + b1y + c1 = 0 and also a2x + b2y + c2 = 0 be the pair of linear equations in 2 variables. The currently representing this equations are said to it is in coincident if;

a1/a2 = b1/b2 = c1/c2

Here, the given pair that equations is called consistent and also they have the right to have infinitely plenty of solutions.

Coincident currently Example

Go with the instance given listed below to understand how to use the formula that coincident lines.

Example: Check whether the present representing the pair of equations 9x – 2y + 16 = 0 and also 18x – 4y + 32 = 0 are coincident.

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9x – 2y + 16 = 018x – 4y + 32 = 0

Comapring the above equations with a1x + b1y + c1 = 0 and a2x + b2y + c2 = 0,

a1 = 9, b1 = -2, c1 = 16

a2 = 18, b2 = -4, c2 = 32


a1/a2 = 9/18 = 1/2

b1/b2 = -2/-4 = 1/2

c1/c2 = 16/32 = 1/2

⇒ a1/a2 = b1/b2 = c1/c2

Therefore, the present representing the given equations space coincident.

This deserve to be shown graphically as:


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