# Generic Rectangle help

• Mar 3rd 2008, 02:21 PM
KuddlyKero
Generic Rectangle help
AHHHHHH!! I need help fast! Ummm...

I need to know the answers to these:

Apparently you are supposed to make a generic rectangle but ive tried already......
(Oh and I dont know to to make xsquared so ill just put xs!)
1)xs - 6x + 8
2)xs - 2x - 8
3)xs + 2x - 8
4)xs + x - 20
5)xs - x - 20

If I could get the answers to all of them I would be really happy!
• Mar 3rd 2008, 03:16 PM
XIII13Thirteen
I'm not quite sure what you are asking. You might recall in geometry that the parameter of a rectangle is $2l+2h$. You can set up the equation in several ways as you have a very broad domain. You can set up the equation in the form of minimums and maximums if this is for calculus. What class is this for? Maybe I'm just not understanding the question. Can anyone help out here?

Also, to note exponents just write the coefficient and the power with a carat (^). So in the case of x squared you'd say x^2. It's easier to read that way. If you insert the x^2 into the math brackets (it's the Sigma symbol in the reply/post "advanced" screen) it'll look like this $x^2$. Hope that helps.
• Mar 3rd 2008, 03:21 PM
ath3na
homework guideance...
What do you mean by get the answers to these? Are you looking for a different way to express them? are you looking for the values of x which make the expression zero? The area under them? What have you tried?

If its the normal homework question it will probably be finding the roots of the equations (values of x that make it equal to zero), find what is called the quadratic formula and read up on it, if you just find the formula that will be enough to instantly answer your problems, it's just a case of plugging the numbers in....

Just telling you the answers wouldn't help anyone would it?
• Mar 3rd 2008, 03:25 PM
XIII13Thirteen
Hint for 1.)

$x^2-6x+8$ is the same as $(x-2)(x-4)$. Multiply them out and see