Transcript PrecalculusAndYou

M305G – Precalculus and You
Chapter 1
What You Need To Know
First Day Handout
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Grading – heavy on homework
Final – on the last day
Quizzes – every week
Participation – every day
Classroom Rules
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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
FOIL,
BIATCH
Math Horror Number 1
(a  b)  a  b
2
2
2
(a  b)  (a  b)( a  b)  a  2ab  b
2
2
2
Math Hall of Horrors
Math Horror Number 2
ab  a  b
a  b cannot be simplified !!
Math Hall of Horrors
Math Horror Number 3
a
a a
 
bc b c
3
3 3
3
  
84 8 4
8
a
cannot be simplified !!
bc
Math Hall of Horrors
Math Horror Number 4
Assume p>0, find all values of x such that
x p
2
x
p
x p
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 Horrors
x2 + 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
Find all values of x such that:
ax2 + bx + c = 0
two solutions for x
One for the
minus
One for the
plus
 b  b  4ac
x
2a
2
Quadratic Equation
3x2 + 5x + 2 = 0
Quadratic Horrors
4x2 = 7x -3
4x  7x  3
2
2x  7x  3
4x2 -7x + 3 = 0
There are only two ways that you
should attempt this problem.
Factoring or the quadratic equation.
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….