Straight Line Calculator
Straight Line Calculator
Straight Line Calculator helps calculating the equation of a Straight Line given two points
What is a Straight Line?
In mathematics, the a Straight Line is a line traced by a point traveling in a constant direction.
The Formula of a Straight Line
The Equation of a Straight Line is:
Y = a + mX
Where:
a = the Intercept
b = the Slope
What is Intercept?
In mathematics, the Intercept of a line is a the point where a line or curve crosses the y-axis of a graph. In other words: find the y value when x equals 0.
What is Slope?
In mathematics, the slope or gradient of a line is a number that describes both the direction and the steepness of the line. Slope is often denoted by the letter m; there is no clear answer to the question why the letter m is used for slope, but it might be from the "m for multiple" in the equation of a straight line "y = mx + b". Slope is calculated by finding the ratio of the "vertical change" to the "horizontal change" between (any) two distinct points on a line. Sometimes the ratio is expressed as a quotient ("rise over run"), giving the same number for every two distinct points on the same line. A line that is decreasing has a negative "rise". The line may be practical - as set by a road surveyor, or in a diagram that models a road or a roof either as a description or as a plan.
The Formula of the Slope
Given two points - 1 and 2, the slope is calculated using the following formula:
m = (y2-y1) / (x2-x1)
In the above example: (X1,Y1) = (8,5) and (X2,Y2) = (2,3)
m =(3 - 5) / (2 - 8) = -2 / -6 = 1/3
The Formula of the Intercept
To calcualte the Intercept, you shout first find the slope (1/3).
Given two points - 1 and 2, the Intercept is calculated by choosing either of the points you were given and substitute those coordinates into the equation.
Given the point (X1,Y1) = (8,5), slove the following equation:
5 = a + 1/3 .8
5 = a - 2.67
a = 2.33
The Formula of a Straight Line?
The Equation of the Straight Line is therefore:
Y = 2.33 +0.33 X