In this case both the slope and the y intercept are known and the equation can be written directly. For example if the slope is -2 and the y intercept is (0,6), then the equation is In this case the ...

[a,b,c,d] representing two points (a, b) and (c, d), return a string representation of the slope of the line joining these two points. For an undefined slope (division by 0), return undefined . Note ...

Horizontal lines run left to right, parallel to the horizon, with slope 0 and equation y = k. Vertical lines run top to bottom, perpendicular to the horizon, with undefined slope and equation x = k.