7.Slope,+Slopes+of+Parallel+Lines+&+Slopes+of+Perpendicular+Lines+(3.4)

=﻿ ﻿Slope, Slope of Parallel Lines, and Slope of Perpendicular Lines = = By: Paige Drummond = = Melissa Le = = Sydney Campo = To find slope- The slope intercept formula= Y=MX+B

Y=the Y corodinate (X,Y)- don't use M= the slope of the line X= the X cordinate-don't use B= the Y-intercept (the point where the line crosses the Y-axis)

Point Slope Formula-

Slope=

Slope of lines

Negative Slope

Positive Slope-

Zero Slope- Undefined Slope-

Slope of Parallel Lines- In a cooridinate plane two non-vertical lines are parallel if and only if they have the same slope.

Slope of Perpendicular Lines- In a coordinate plane two non-vertical lines are perpendicular if and only if the product of their slope is -1.

How to Calculate the Slope of Perpendicular Lines-
 * The product of the two slopes must be -1
 * They also must be opposite recipricals

Example- Then, of course, you would make it negative for the opposite part.

Problem One- By:Paige Drummond Find the Line Perpendicular to this line.



Answer- First you must find the slope using the formula for finding slope. You can use any two points but for this problem we will use (-2,3) and (2,1). The slope is negative one and a half. Then to place it on the line pick a Y-intercept. The easiest on is always (0,0). Then you count over negative one and up two. Repeat this untill you have your line.

Practice Problem 2- Melissa Le Solve for //y//. Use the resulting equation to find the slope of the line. 9//x// – 2//y// = –18

Answer:step-by-step

Using the Addition Property, add –9//x// to both the sides. (–9//x//) + 9//x// – 2//y// = (–9//x//) + (–18) Simplify. –2//y// = (–9//x//) – 18

Using the Multiplication Property, multiply both sides by –1/2. Simplify. Simplify the expression using the Distributive Property. Here distribute –1/2. The equation is in the slope–intercept form, //y// = //mx// + //b// Hence, the slope is 9/2.

online worksheet [] http://www.themathpage.com/alg/slope-of-a-line.htm

Practice Problem: Find the slope of the line given in the graph below. By: Sydney Campo

 Answer:

Two sets of coordinates that we could use to solve this problem are (-3,0) and (0,5)

gives us the answer to our "run".
Rise= 5 Run= 3 The slope = rise/run = 5/3