Sunday, August 23, 2009

Devin's Reflection #1

Ok. This week has been truly exhausting for me. It wasn't to bad, but it wasn't to great. All the information was completely new to me. At the beginning of this week I didn't know the difference between factoring, using the quadratic formula, and completing the square. I understand them now. The steps to completing the square have really helped:

Problem #13 from test
x2-4x=9

1. Divide the linear term by 2 and square it
4/2= 2; (2)2=4

2. Add to both sides
x2-4x+4=13

3. Factor left side2
(x-2)2=(square root of) 13

4. Square root both sides
x-2=(square root of) 13

5. Solve for variable
x=2+-(square root of) 13
(2+-(square root of 13,0)

Graphing parabolas were a challenge also. The main difficulty for me was fing the axis of symmetry and the vertex. I do not know what formula I should us for those equations. The discriminate ws a challenge at first also. The imaginery numbes are easy but I have trouble remembering the chart. I understand everything eventually.
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3 comments:

  1. ArchimedesAugust 24, 2009 at 12:18 PM

    Great reflection Devin! I know it is hard catching up with our honors class but you are doing well.

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  2. KaneAugust 26, 2009 at 7:18 PM

    If you can remember the formula for finding the axis of symmetry (-b/2a) then finding the vertex should be easy. The axis of symmetry will be your x value. To find the y value simply plug in your axis of symmetry into the original function. Your vertex will be (-b/2a, (f)-b/2a).

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  3. alainaAugust 26, 2009 at 10:42 PM

    I always have problems with these. Its okay.
    Just think,
    1st. open up/down
    2nd. y-intercepts (let X=0)
    3rd. x-intercepts (simple algebra, factoring, quadratic formula, completing the square)
    4th. axis of symmetry (**your formula X=(-b/2a))
    5th. finally your vertex. (you plug in what you got for your axis of symmetry into the origional formula.)
    HAPPY HINTS!**
    *numero uno-when determinging if your parabola opens up or down, refer to the number with the highest exponent(leading term) if it is positive, open up, negative=down.
    *numero dos-when finding your y-intercepts, ALWAYS let X=0, it makes your life sooo much easier.
    *numero tres-make sure you check to see if SIMPLE ALGEBRA or FACTORING can be used FIRST, if neither works, go for completing the square or quadratic formula.
    *numero quatro-**always always always remember that it is ***X=***(-b/2a)**
    *letter five-whatever you get for your axis is equal to X!! plug that number in for X in the origional equation and solve!
    :)

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