Section 6-2 Slope-Intercept Form

How to Graph a Linear Equation It must be in the slope – intercept

form. Which is:

y = mx + b

slope y-intercept

Y - intercept Is where the

point crosses the y – axis.

When graphing you start your starting point on the y-axis

Graph the equation y = 3x-5

Before you graph you must answer the following: Is it in the form? Y-intercept? Is the slope positive

or negative? What is the slope? Graph?

Graph the equation y = -1/2x +2

Before you graph you must answer the following: Is it in the form? Y-intercept? Is the slope positive

or negative? What is the slope? Graph?

Graph the equation y+5 = 4x

Before you graph you must answer the following: Is it in the form? Y-intercept? Is the slope positive

or negative? What is the slope? Graph?

Write an linear equation for the following: m = 2/3 , b = -5

m = -1/2 b = 0

m = 0 , b = -2

Example: Does the point (8,4) lie on the line

with the equation y = 3/4x - 2

Example – Write an equation for the line

What about slopes of zero? This is special situations!!!

Horizontal Lines

y = 3 (or any number)Lines that are horizontal have a slope of zero.  They have "run",

but no "rise".   The rise/run formula for slope always yields

zero since rise = 0.y = mx + by = 0x + 3

y = 3This equation also describes what is happening to the y-coordinates on the line.  In this case, they are

always 3.

What about slopes of no slope? This is special situations!!!

Vertical Lines

x = -2 (or any number)Lines that are vertical have no slope (it does not exist).  They have "rise", but no "run".  The

rise/run formula for slope always has a zero denominator and is

undefined.These lines are described by what

is happening to their x-coordinates.  In this example, the x-coordinates are always equal to

-2.

Homework

Pg320-3212-54 every 4

58-6266, 78a