From b114283c1ed207f2d83eeacd916795c595b99f62 Mon Sep 17 00:00:00 2001 From: philip1077 Date: Mon, 12 Nov 2018 05:26:24 -0500 Subject: [PATCH] Added examples for slope and one point. Made easier to understand. (#21339) --- .../mathematics/equation-of-a-line/index.md | 20 ++++++++++++++++++- 1 file changed, 19 insertions(+), 1 deletion(-) diff --git a/guide/english/mathematics/equation-of-a-line/index.md b/guide/english/mathematics/equation-of-a-line/index.md index 2d0f1f1353..1439bd8b4e 100644 --- a/guide/english/mathematics/equation-of-a-line/index.md +++ b/guide/english/mathematics/equation-of-a-line/index.md @@ -4,15 +4,33 @@ title: Equation of a Line ## Equation of a Line ### For a Given Slope and y-intercept (Standard Form): -Let `m` be the slope of the line and `b` be the y-intercept. (Note that the y-intercept is the point at which the given line crosses the y-axis). Then the equation of a line is: +Let `m` be the slope of the line, and `b` be the y-intercept. (Note that the y-intercept is the point at which the given line crosses the y-axis). Then the equation of a line is: `y = mx+b` +Keep in mind that you still have `y` which is the Dependant Variable and `x` the Independant Variable meaning that `x` can be any value, whereas `y` will be a value based off of what `x` is. + + ### For a Given Slope and One Point through which the Line Passes (Point-Slope Form): Let `m` be the slope of the line and `(x1, y1)` be the co-ordinate of the point through which the given line passes. Then the equation of a line is: `(y - y1) = m(x - x1)` +To break this down a bit, substitute your slope value (ex. 2) in for m: + +`y=(2)x+b` + +Next, substitute your point (ex. (3,2)) in for `x` and `y`. Remember that the points are `(x,y)` in that order. Always. + +`(2)=2(3)+b` + +Solve for `b`. Then put the equation back into `y=mx+b`. + +`-4 = b` + +Therefor your final answer is: `y=2x-4` + + ### For Two Points through which the Line Passes: Let `(x1, y1)` and `(x2, y2)` be the co-ordinates of two points through which the given line passes. Then the equation of a line is: