Lesson 1-2 Slopes of Lines

Objective:

Objective:

To find the slope of a line and to determine whether two lines are parallel, perpendicular, or neither.

Slope

SlopeA number measuring the steepness of the line relative to the x-axis.

Slope

12

12

xx

yym

SlopeHorizontal lines have a slope of ???

SlopeVertical lines have a slope of ???

SlopeLines with a positive slope slant ???

SlopeLines with a negative slope slant ???

SlopeThe slope of the equation y = mx + k is ???

SlopeThe slope of the equation y = mx + k is ???

This is called slope-intercept form.

What are the slope and y – intercept of the line 7x + 13y = 26?

SlopeWhat do you know about the slopes of parallel lines?

SlopeWhat do you know about the slopes of perpendicular lines?

A line l has equation x + 2y = 5. What is the slope of a line (a)

parallel to l? (b) perpendicular to l?

The equations of three lines are given. Which lines are parallel and

which are perpendicular?

a. y = ¾ x – 7b. 4x + 3y = 10 c. 3x – 4y = 11

Find the value of k if the line joining (2, k) and (4, 5) and the line y = 3x + 1 are (a) parallel,

(b) perpendicular.

Assignment:

Pgs. 11 - 13 C.E. 1-14 all, W.E. 1-27 odd