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Re: Where Simple Problems?
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Cliff Bowman
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Dec 23, 2004 08:40 PST
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Nathan:
the place to go [Pi states unequivocally] is: IRC Undernet #math !!!
many ppl there enjoy helping with such problems.
Good luck!
additional notes:
you came up with the correct equation (half credit!) for the specific
problem you listed. at that point, one has a few options, depending on the
class level and orientation.
1. try educated guessing...assume integer solution set, and try, say, w=10.
too little, okay, try w=12. success. that, of course, is not generally
gunna get you far in the 'real' world, but it is a problem solving
approach/technique.
2. try simplifying and factoring--this can often work quite well.
3. you have a quadratic equation (highest power of variable is 2), so plug
values into quadratic formula, and use only positive-value solution as we
are solving for an actual length.
4. if class has not covered quad. formula, then solve by 'completing the
square'--it always works, the quad.formula is just a general solution to
completing the square:
x^2 + 6x = A <--- in this case, we say b = 6, to complete the square,
add square of b/2 to both sides.
x^2 + 6x + 3^2 = A + 3^2
(x+3)^2 = A + 3^2
x+3 = sqrt(A+9) <---normally plus or minus the square root (here we only
want the positive root)
x = sqrt(A+9) - 3
5. some teachers use novel approaches to engender creative thinking, etc.
your son should have notes from class and number of AT LEAST one good
student in that class. what method was covered in class? usually there is
at least one sample problem, how was it solved?
6. the teacher sucks is not a valid excuse, even when it comes from our own
children. :)
Be well, PiMaster aka FatherPi
----- Original Message -----
From: "Nathan Stanford" <adm-@cftipsplus.com>
To: <underne-@topica.com>
Sent: Thursday, December 23, 2004 7:22 AM
Subject: [undernet-math] Where Simple Problems?
Where can I go to find people who might help me with this problem?
Simple Question...
The length of a rectangle is 6 centimeters more then its width. The area
is 216 square centiemeters. What are the dimensions?
My son is solving polynomial
However it is a trinomial I think.... it has been so long I can not
remember how.
cm = centimeters
A=WL
216cm² =W(W+6cm)
W²+ 6cmW - 216cm² = 0
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