1.C Warm – UP

• Solving Multi-Step Inequalities

How are solving equations and inequalities the same/different?

1.b quiz/class work

• Using multi-step equations to solve word problems

Everybody Get-up

Come to the board and write down something you remember about:

• slope• the slope intercept form of a line • graphing – A point – A line

Lesson 1.d:understand the concepts of slope and rate of change

After this lesson you will be able to …• Determine the slope of a line

• Determine if a line rises, fall, is horizontal or vertical

• Determine if two lines are parallel, perpendicular or neither

Slope Video

• http://www.youtube.com/watch?feature=player_embedded&v=bRGxIJRPZjQ

What Do We Mean by Slope?:

• How much a line goes up vertically compared to how much it goes out horizontally.

• rise/run or change in y/change in x

So, What Good Is That?

• It tells you exactly what your equation should look like when graphed!

The Slope FormulaFinding Slope From Two Points:

. where,

:formula by the

given is ),( and ),( scoordinatewith

points twocontaining line a of slope The

2112

12

2211

xxxx

yym

yxyx

m

Mix and Match 4 times:

• Raise your hand to find a partner.• Use your card and your partner’s to find the

slope of the line passing through your points.• Check your results and make sure they match.• Switch cards.• Raise your hand to find another partner.• You may not partner the same person more

than once.

Finding Slope From a Graph:

m = m = m =

Two Special Cases:

Horizontal Line:

m =

Equation:

Vertical Line:

m =

Equation:

Let’s Sum Things Up:

• If m is positive:

• If m is negative:

• If m is 0 (zero)

• If m is undefined:

Parallel Lines:

• Parallel lines have the same ______.

Determine if is parallel to . M (-3,-4), A (7,-10), T (-1,6), H (4,3)

MA TH

Perpendicular Lines:

• Perpendicular lines have slopes which are negative inverses (reciprocals) of each other.

Example

Are these perpendicular?• Line AB: A(4, 8) B(-3, 5)• Line CD: C(1, 9) D(4, 2)

Use your point with the point (3,-1) and do the following:

• Find the slope of the line passing through your point and (3,-1).

• Find the slope of a line passing parallel to your line.

• Find the slope of a line perpendicular to your line.

TOTD

• 1.b, 1.c & 1.d

1.d Homework

• 2-3 Study Guide 1 – 4, 7, 10-12