X and Y Intercept Formula as the name suggests, is the formula to calculate the intercept of a given straight line. An intercept is defined as the point at which the line or curve intersects the graph’s axis. The intercept of a line is the point at which it intersects the x-axis or the y-axis. If no axis is provided, the y-axis is normally used. When a point crosses the x-axis, it is referred to as the x-intercept. When a point crosses the y-axis, it is referred to as the y-intercept. Â It is represented by the letter ‘c’. A line can either have an x-intercept or y-intercept or both of them.
Intercept Definition
An intercept is defined as the point where the line or curve crosses the axis. If the point is on the x-axis then it is called the x-intercept and if the point is on the y-axis, then it is called the y-intercept.
We generally represent the x-intercept by a and the y-intercept by b. The equation of the line making a and b intercept on the x and y axis respectively is,
x/a + y/b = 1
What is X-Intercept?
The x-intercept of a line is the point at which the line intersects the x-axis. So, to find the x-intercept put y = 0 in the equation of a line.Â
X-Intercept Formula
The formula of x-intercept for slope-intercept equation y = mx + c is given by,
x-intercept = -c/m
Thus, (-c/m, 0) is the coordinate of x-intercept.
Where,
- (0, c) is the y-intercept,
- m is the slope of the given line.
Derivation of X-Intercept Formula
Consider a line given in the slope intercept form y = mx + c, where the line has a intercept (c, 0) and has a slope m.
Put y = 0 in the equation to get the x-intercept.
⇒ 0 = mx + c
Solve the equation for x.
⇒  mx = -c
⇒ x = -c/m
This derives the formula for x-intercept.
What is Y-Intercept?
The y-intercept of a line is the point at which the line intersects the y-axis. So, to find the y-intercept, put x = 0 in the equation of a line.Â
Y-Intercept Formula
The formula of y-intercept for slope-intercept equation y = mx + c is given by,
y-intercept = c
Thus, (0, c) is the coordinate of y-intercept.
Derivation of Y-Intercept Formula
Consider a line given in the slope-intercept form y = mx + c, where the line passes through the point (0, c) and has a slope m.
Put x = 0 in the equation to get the y-intercept.
⇒  y = m (0) + c
⇒  y = 0 + c
⇒  y = c
This derives the formula for y-intercept.
How To Find X And Y Intercept?
To find the x-intercept we put y = 0 in the given function and then solve for x. The resultant value of x is the x-intercept of the given function.
Example: Find the x-intercept of the linear equation 2x + 3y = 7.
Solution:
For the x-intercept of the linear equation 2x + 3y = 7
Put y = 0,
2x + 3×0 = 7
⇒ x = 7/2
Thus, the x-intercept of 2x + 3y = 7 is 7/2.
To find the y-intercept we put x = 0 in the given function and then solve for y. The resultant value of y is the y-intercept of the given function.
Example: Find the y-intercept of the linear equation 3x + 4y = 12.
Solution:
For the y-intercept of the linear equation  3x + 4y = 12
Put x = 0,
3×0 + 4y = 12
⇒ y = 12/4
⇒ y = 3
Thus, the y-intercept of 3x + 4y = 12 is 3.
Intercept Form of a Straight Line
Intercept Form of a Straight Line, mathematically given byÂ
x/a + y/b = 1
Where,Â
- a is the x-intercept of the straight line
- b is the y-intercept of the straight line
Intercept Graph
We know that the intercept is the points on the axes that are cut by a straight line. The point on the x-axis is called the x-intercept, and the point on the y-axis is called the y-intercept. The image added below shows the line, with x and y intercepts.
Â
For Point-Slope Form
The point-slope form of a line is given as follows:
y – y1 = m(x – x1)
where:
- (x1, y1) is a point on the line
- m is the slope of the line.
To find, the x and y-intercepts of the given line,
Here, rearranging the equation, we get
y = mx – mx1 + y1
⇒ y = mx + (-mx1 + y1)
Comparing it with y = mx + c, we get
c = -mx1 + y1, which is the y-intercept of the given line.
and x-intercept is -c/m = (mx1 – y1)/m = x1 – y1/mÂ
Thus, x and y-intercept of the given y – y1 = m(x – x1) are x1 – y1/m and  -mx1 + y1 respectively.
Uses Of X And Y Intercept
There are various use cases of X And Y Intercepts, some of which are as follows:
- We use the concept of intercepts in curve tracing, for example, we have an unknown curve, so intercepts are one of the first parameters in the analysis of the curve.
- Both intercepts in whichever quadrant forms a triangle, whose area can calculate by 1/2 times the product of intercepts.
- By plotting both intercepts on the coordinated axes, we can plot the graph of the linear equation.
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Sample Problems X and Y Intercept Formula
Problem 1: Calculate the x-intercept of the equation x + 3y = 8.
Solution:
We have the equation as, x + 3y = 8.
Put y = 0 to find the x-intercept and then solve the equation for x.
⇒  x + 3 (0) = 8
⇒  x = 8
So, the x-intercept for the equation is (8, 0).
Problem 2: Calculate the x-intercept of equation 4x + 7y = 10.
Solution:
We have the equation as, 4x + 7y = 10.
Put y = 0 to find the x-intercept and then solve the equation for x.
⇒  4x + 7 (0) = 10
⇒  4x = 10
⇒ x = 10/4
⇒  x = 5/2
So, the x-intercept for the equation is (5/2, 0).
Problem 3: Calculate the y-intercept of equation 4x + 3y = 24.
Solution:
We have the equation as, 4x + 3y = 24.
Put x = 0 to find the y-intercept and then solve the equation for y.
⇒ 4(0) + 3y = 24
⇒  3y = 24
⇒  y = 24/3
⇒  y = 8
So, the y-intercept for the equation is (0, 8).
Problem 4: Calculate the y-intercept of equation 8x + 5y = 25.
Solution:
We have the equation as, 8x + 5y = 25.
Put x = 0 to find the y-intercept and then solve the equation for y.
⇒  8(0) + 5y = 25
⇒ 5y = 25
⇒  y = 25/5
⇒  y = 5
So, the y-intercept for the equation is (0, 5).
Problem 5: Calculate the x- and y-intercept of equation 4x2 + 9y2 = 25.
Solution:
We have the equation as, 4x2 + 9y2 = 25.
Put y = 0 to find the x-intercept and then solve the equation for x.
⇒  4x2 + 9 (0)2 = 25
⇒  4x2 = 25
⇒  x2 = 25/4
⇒  x = ±5/2
So, the x-intercept for the equation is (±5/2, 0).
Put x = 0 to find the y-intercept and then solve the equation for y.
⇒  4 (0)2 + 9y2 = 25
⇒  9y2 = 25
⇒  y2 = 25/9
⇒ y = ±5/3
So, the y-intercept for the equation is (0, ±5/3).
FAQs on X and Y Intercept Formula
Q1: What is the X-Intercept Formula?
Answer:
For straight line y = mx + c, formula for x-intercept is given as follows:
x-intercept = -c/m
Thus, Â (-c/m, 0) is the coordinate of x-intercept.
Where,
- (0, c) is the y-intercept,
- m is the slope of the given line.
Q2: What is the Y-Intercept Formula?
Answer:
For straight line y = mx + c, formula for y-intercept is given as follows:
y-intercept = c
Thus, (0, c) is the coordinate of y-intercept.
Q3: How do you find the X-Intercept of a Linear Equation?
Answer:
As x-intercept is the point where the line intersects the x-axis. Thus, we can find the coordinate of the x-intercept by putting (x,0) in the given linear equation and then finding the value of x. Thus, (x, 0) is the coordinate of the x-intercept.
Q4: How do you find the Y-Intercept of a Linear Equation?
Answer:
As y-intercept is the point where the line intersects the y-axis. Thus, we can find the coordinate of the y-intercept by putting (0, y) in the given linear equation and then finding the value of y. Thus, (0, y) is the coordinate of the y-intercept.
Q5: What is the relationship between X-Intercept and Y-Intercept?
Answer:
The relationship between the x and y-intercept is the slope of the line.Â
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