Graphing Straight Lines:

y = mx + c

In the above equation/formula, m is the gradient of a line. m is calculated through dividing rise by run. Rise is equivalent to y2 - y1 (the second point must be the furthest along the x-axis), run is equivalent to x2 - x1. It is worth noting that we look to rise to check if the gradient is negative. c is equivalent to the y-intercept. c is the value of y when x is equal to 0 and is calculated by substituting x = 0 into the equation and solving for y.

Input values below into the respective input boxes. (Note: you can hover your mouse along the x-axis to see points on the line with that x position, the mouse's coordinates will also be displayed)

Manipulating the equation:

In the rule y = mx + c it is worth noting that m rotates the line while c moves the line along the y-axis. To demonstrate in the below graph you can experiment with the sliders to see the effects of changing these variables (the dotted line is y = c to show the y-intercept clearly):

Finding the Equation of a Straight Line:

In the below graph you can move the points by clicking and dragging the points, or set the point's coordinates in the below inputs to find the equation of the line formed by those points and receive information about it.

Point 1:

Point 2:

Comparing linear equations:

Below you can enter the equations for multiple linear equations to see them compared.

(Note: currently you can only add lines and compare them on the graph below)