M305G – Precalculus and You

Chapter 1

What You Need To Know

First Day Handout

• Grading – heavy on homework

• Final – on the last day

• Quizzes – every week

• Participation – every day

Classroom Rules

• Homework due at the beginning of class

• Cheating is lame

• Cell phones are equally lame

• No smiling

M305G – Precalculus and You

Chaper 2

What You Should Already Know

Math Hall of Horrors

• Five math mistakes that send Michael over the edge

Math Horror Number 1

222 2))(()( bababababa

222)( baba

FOIL, BIATCH

Math Hall of Horrors

baba

Math Horror Number 2

!!simplified becannot ba

Math Hall of Horrors

c

a

b

a

cb

a

!!simplified becannot cb

a

Math Horror Number 3

8

3

4

3

8

3

48

3

Math Hall of Horrors

px 2

px

Math Horror Number 4

Assume p>0, find all values of x such that

px

Math Hall of Horrors

Math Horror Number 5

Not being able to solve quadratic equations.

M305G – Precalculus and You

Chapter 3

Quadratic Equations The Easy Way

Quadratic Equations

There are only two ways that you should ever try to solve a polynomial equation where the lead term is x2

1) Factor, using the zero product principle

2) Use the quadratic equation

Factoring – Zero Product Principle

If xy = 0, then either:

1. x must be zero OR

2. y must be zero OR

3. both must be zero

x2+5x+6 = 0

(x+2)(x+3) =0

x+2 = 0 or x+3 = 0

x = -2 or x = -3

Factoring Horrorsx2 + 3x = 4

x(x+3) = 4

x = 0 or x = 3

x2 + 3x – 4 = 0

(x+4)(x-1) = 0

The key is to make sure the right hand side is zero

Quadratic Equations

There are only two ways that you should ever try to solve a polynomial equation where the lead term is x2

1) Factor, using the zero product principle

2) Use the quadratic equation

Quadratic Equation

ax2 + bx + c = 0

Find all values of x such that:

a

acbbx

2

42

two solutions for x

One for the plus

One for the minus

Quadratic Equation

3x2 + 5x + 2 = 0

Quadratic Horrors

372

374 2

xx

xxThere are only two ways that you should attempt this problem. Factoring or the quadratic equation.

4x2 = 7x -3

4x2 -7x + 3 = 0

When should you use the quadratic equation instead of factoring?

If you spend more than 15 seconds trying to figure out how to factor it, use the quadratic equation instead

The quadratic equation always gives me an

answer!! Factoring is for the birds.

AWWWWWWWK

Math Hall of Horrors

Math Horror Number 5

Not being able to solve quadratic equations.

Use one of two methods:

factoring or the quadratic equation

Otherwise….