Thursday, February 21, 2008
Chapter 3 Homework Assignments
Section 3.1 pg.94/21-26
Section 3.2 pg.100-102/2-30(evn)
Assignment 11
Section 3.3 pg.107-109/2-20(evn)
Assignment 12
Section 3.4 pg.115-117/1-39(odd)
Assignment 13
Section 3.4 pg.115-117/2-40(evn)
Assignment 14
Click here for Homework on completing the square and related craziness
Assignment 15
Section 3.5 pg.125-126/1-23(odd),24
Study Group Assignment
pg129-130/chapter Test/all
Also review the following concepts
1. Taking an equation and putting it in function notation
2. Evaluate the value of a function given a specific value for x
3. Identify independant and dependant variables
4. Find the x and y intercepts from functions and explain their meaning
5. Constuct and interpret graphs of functions accurately
6. Write linear equations for a table or word problems
7. Write a piece wise linear function relating to tax, phone plans or pay of sales people with quotas
8. The dreaded variation problems
Wednesday, October 10, 2007
Completing the Square and Related Craziness
FOIL
- (x+2)^2
- (x-3)^2
- (x-4)^2
- (x+5)^2
- (x+3/4)^2
- (x+k)^2
- (3x+2)^2
- (3x-1)^2
- (4x-4)^2
- In a perfect square trinomial (the result of squaring a binomial) ______ of the coeffiecient middle term is always equal to the square root of the last term.
- Another way of saying that is the _______ of ____ of the middle term is ______ to the last term.
Analyze:
Determine if the following are perfect square polynomials. If they are write them as the square of a binomial. If not show me why and write "not a perfect square".Here's an example of what I'm looking for:
Example: x^2 + 12x + 36
Possible Answers:
"Yes, because 12 divided by two is 6 and 6^2 = 36. The last term is the square of half the coefficient of the middle term."
or
"Yes, because the square root of 36 doubled is 12"
- x^2 + 5x + 10
- x^2 + 3x + 9
- x^2 + 6x + 12
- x^2 - 2x + 1
- x^2 - 5x + 25
- x^2 -3x + 9/4
- x^2 - 8x + 16
Evaluate:
Find the value of c for which ax^2 + bx + c is a perfect square trinomial
Hint: c must always equal (b/2)^2 for ax^2 + bx + c to factor into (x + b/2)^2
- x^2+ 6x + c
- x^2 + 14x + c
- x^2 - 8x + c
- x^2 - 16x + c
- x^2 + 5x + c
- x^2 -2/5x + c
Solve:
Finally use the method of completing the square to solve the following problems
Example: 2x^2 -3x = 5
Explanation:
Divide everything by 2 to get x^2 -3/2x = 5/2
then divide -3/2 by 2 (that is -3/4) and add the square of -3/4 to both sides.
That is, add 9/16 to both sides.
Your result is x^2 -3/2x + 9/16 = 5/2 + 9 /16.
Now the left side can be factored to the square of a binomial and the right can be simplified into 41/16.
So x^2 - 3/2x + 9/16 becomes (x - 3/4)^2 = 41/16
This result can be solved by employing the squareroot property in the same fashion as you did for the ones above.
- x^2 + 6x = 5
- x^2 - 16x = -70
- x^2 +18x = -6
- y^2 + 20y = -40
- m^2 + 18m + 100 = 0
- 2x^2 - 16x = 6
- 5t^2 - 60t = -20
- 2x^2 +16x -8 = 0
- m^2 + 8m -9 = -5
Hint: On the 6 - 8, you will need to divide by the
coeffecient of the x^2 term before doing anything else.