Algebra Questions!!!

[ZzKingz]

Me and my supercharged calculus brain have some nerdy questions:
1. What is a quadratic???
2. Is there a way to write "if" in an equation? For example, If x<2, then y=2x+3, otherwise, x=2.
3. Is there a way to represent leveling out, like something accelerating, then leveling out at a certain point?
4. Can you have three or more variables? Ex. y=cx+2x
5. what does "Σ" mean?
6. What is uppercase pi? not 3.14159... but Π
7. Is there a gamma in Math? (Γγ)
8. Why is π 3.14159...? why that number? knowing math patterns, general ideas usually arent specific numbers. Is pi a special number?
My battery is dying so i must go... Please answer in detail these are questions i need answers to!

[Gumleaf]

moved: ramblings of the wise >>> education & careers

[Kaleidoscope Eyes]

I don't know all of the answers, and it's a little late to my brain may not be working properly, but as far as I'm able to work out:

1. A quadratic equation is an equation of the form ax(squared) + bx +c = 0, where a, b, and c are real numbers and a =/= 0.
2. I don't believe so, other than writing it out in English the way you just did... If there is I don't remember it. xD
3. I don't think there is. If you were to write an equation to represent the height of a projectile at x number of seconds after being launched at so many mph at whatever angle, yatta yatta, of course eventually all values of x are going to result in an answer of 0ft, because the object will eventually stop moving and just be sitting on the ground. You don't see that written out when you look at the equation, though, you have to figure out for yourself which values of x will make the equation equal to 0.
4. Sure. In fact, when you get higher in math, you'll find yourself doing equations with three variables pretty often, and there's no reason why you can't have more than that. 2x + 4y(z-7) is an example of an expression with three variables.
5. I know I learned that in Pre-Calc... but it was a few years ago and it's almost 1am. Someone else will have to answer this one. xD
6. I don't know that there is a value or a meaning for uppercase pi. I'm pretty sure the lowercase is all that's used.
7. All sorts of Greek letters are used in math and science, but I don't know for sure about gamma.
8. Yes, it is a special number. Pi is a constant value, which represents the ratio of any circle's circumference to its diameter. That's why you use it a lot when working with circles in geometry. Since the actual value goes on forever, we use a symbol to represent it; that symbol happens to be pi.

[delete.please]

2. Yeah, you use a piecewise function. I can't really draw it out on here, so you'll have to google it, but what it pretty much says is "in this interval use <whatever> equation, and in another interval use <another equation>"

3. Something can "level out" as it approaches an asymptote. Or, if your talking about a point at which it slowly stops and turns around, it's called a relative maximum or minimum.

[INFERNO]

1. What is a quadratic???

Any equation where the highest power is 2, such as x^2.


2. Is there a way to write "if" in an equation? For example, If x<2, then y=2x+3, otherwise, x=2.

I'm not sure how to show it on here but it's easy to handwrite out. Google it to see or else I'm sure my explanation of it will leave you even more confused.


3. Is there a way to represent leveling out, like something accelerating, then leveling out at a certain point?

This can be done through a basic parabola (the graph for a quadratic equation). It would most likely look like an inverted U. Alternatively, it could be a basic dose-response curve, which isn't a parabola but rather a graph where the line rises to a certain point and then just goes horizontal.


4. Can you have three or more variables? Ex. y=cx+2x

Yes, you can have as many variables as you want. However, the more you have, the more complex and time-consuming it will be to determine the values of each.


5. what does "Σ" mean?

It's part of the Greek alphabet and is referred to as capital sigma. It means the sum of. On the bottom of it you would likely have something such as "n=" or whatever your variable is. This is the first number that you summation will start from. On the top of the sigma is a number defining how long the summation will be.

For example, if 6 is on top and x=2 on the bottom, and the equation we'll use is x+2, then:

Σ(x+2) = (2+2) + (3+2) + (4+2) + (5+2) + (6+2) + (7+2)


6. What is uppercase pi? not 3.14159... but Π

It's similar to what Σ means only instead of adding the terms, you simply multiply them.


7. Is there a gamma in Math? (Γγ)

Yes there is, however, to explain it you should understand calculus and some probability or statistics.


8. Why is π 3.14159...? why that number? knowing math patterns, general ideas usually arent specific numbers. Is pi a special number?

I'm not sure off the top of my head why that exact number. You can also question why e=2.71828.... . Your best answer would be to simply Google this history of pi.

Pi is a special number because it's used in numerous applications for mathematics, along with e and other constants.