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New user? Re: A math problem is driving me nuts!
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Posted
5/9/2004; 5:01 PM by Jim RoepckeLast Modified
5/9/2004; 5:01 PM by Jim RoepckeIn Response To
RE: A math problem is driving me nuts! (#6884)Label
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On May 9, 2004, at 4:48 AM, Seth Dillingham wrote:
> On 5/9/04, Jim Roepcke said:
>
>> I need a thorough review of factoring, for one thing.
>
> Factoring is actually very easy, though sometimes it's a little time
> consuming. There are lots of homework-help sites on the net for
> highschoolers that do a good job of walking you through factoring
> quadratic equations and other such things.
Thanks Seth, I'll look for that on the 'net next time I'm looking for
resources and post any good links I find.
This morning I remembered how to factor quadratic expressions (at least
I think these are called quadratic expressions). I was looking at them
yesterday, and could see, intuitively, what was being done, but I
couldn't remember the "algorithm" or pattern for doing it.
x^2 + 2x - 3
I need to find two numbers whose sum is +2 and product is -3. So,
that's +3 and -1. Bing! I remember! Yay! Grade nine is flooding
back. :-)
x^2 + 2x - 3 = (x + 3)(x - 1)
I never forgot how to do the inverse, the expanding bit, because of an
acronym we learned in math class: FOIL. First, Outside, Inside, Last.
Multiply the first terms of each term, then the outside terms, then the
inside terms, then the last terms, and add them. I imagine this is how
everyone is taught this.
(x + 3)(x -1) = x*x + x*-1 + 3*x + 3*-1 = x^2 - x + 3x - 3 = x^2 + 2x -3
This is pretty basic stuff, and obviously nowhere near where I need to
get, but it feels good to remember these patterns again. Now I need to
work through a bunch of these to get it nailed... something I didn't do
the first time around in junior high. I just memorized the pattern and
was satisfied with that. I could do things fast enough that I could
always ace the tests. Thankfully the tests were worth enough, and
homework worth little enough that I would get a half-decent grade just
doing tests. Senior high was different, I did a lot of homework then
so I could get honour roll grades, because I needed those grades to get
into UVic. :-) Also, I always told my parents that I would get good
grades when it mattered... since Junior High grades didn't matter, I
didn't care. I was sick of having meetings with my parents and the
school councillors about my grades and trying to understand why I
didn't do my homework. My answer always was, "it's boring crap, I
already know this stuff, give me something interesting to do and I'll
do it, I ace the tests so quit your complaining!"
Jim
> On 5/9/04, Jim Roepcke said:
>
>> I need a thorough review of factoring, for one thing.
>
> Factoring is actually very easy, though sometimes it's a little time
> consuming. There are lots of homework-help sites on the net for
> highschoolers that do a good job of walking you through factoring
> quadratic equations and other such things.
Thanks Seth, I'll look for that on the 'net next time I'm looking for
resources and post any good links I find.
This morning I remembered how to factor quadratic expressions (at least
I think these are called quadratic expressions). I was looking at them
yesterday, and could see, intuitively, what was being done, but I
couldn't remember the "algorithm" or pattern for doing it.
x^2 + 2x - 3
I need to find two numbers whose sum is +2 and product is -3. So,
that's +3 and -1. Bing! I remember! Yay! Grade nine is flooding
back. :-)
x^2 + 2x - 3 = (x + 3)(x - 1)
I never forgot how to do the inverse, the expanding bit, because of an
acronym we learned in math class: FOIL. First, Outside, Inside, Last.
Multiply the first terms of each term, then the outside terms, then the
inside terms, then the last terms, and add them. I imagine this is how
everyone is taught this.
(x + 3)(x -1) = x*x + x*-1 + 3*x + 3*-1 = x^2 - x + 3x - 3 = x^2 + 2x -3
This is pretty basic stuff, and obviously nowhere near where I need to
get, but it feels good to remember these patterns again. Now I need to
work through a bunch of these to get it nailed... something I didn't do
the first time around in junior high. I just memorized the pattern and
was satisfied with that. I could do things fast enough that I could
always ace the tests. Thankfully the tests were worth enough, and
homework worth little enough that I would get a half-decent grade just
doing tests. Senior high was different, I did a lot of homework then
so I could get honour roll grades, because I needed those grades to get
into UVic. :-) Also, I always told my parents that I would get good
grades when it mattered... since Junior High grades didn't matter, I
didn't care. I was sick of having meetings with my parents and the
school councillors about my grades and trying to understand why I
didn't do my homework. My answer always was, "it's boring crap, I
already know this stuff, give me something interesting to do and I'll
do it, I ace the tests so quit your complaining!"
Jim
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