need some math help

[dullard]

Originally posted by: Vegitto
Oh, wait! I know. I don't know what it's called in English, though .. And I don't think I can give the answer if the only possible outcomes are x=-1 through x=1 and y=0 consistently..

There may be a translation problem (I have no idea what you mean by "y=0 consistantly"). But no, you probably don't know. You probably need to take a few more math courses. It is nice that you are trying to help. But if you don't know what he is solving for, and you haven't had the courses necessary, you aren't helping.

 

[Vegitto]

Originally posted by: dullard

Originally posted by: Vegitto
Oh, wait! I know. I don't know what it's called in English, though .. And I don't think I can give the answer if the only possible outcomes are x=-1 through x=1 and y=0 consistently..

There may be a translation problem (I have no idea what you mean by "y=0 consistantly"). But no, you probably don't know. You probably need to take a few more math courses. It is nice that you are trying to help. But if you don't know what he is solving for, and you haven't had the courses necessary, you aren't helping.

I meant that for every possible input (x=-1, x=0 and x=1) y equals (hence the '=') zero (0).

 

[dullard]

Originally posted by: Vegitto
I meant that for every possible input (x=-1, x=0 and x=1) y equals (hence the '=') zero (0).

Why are those the only possible inputs? For example, when x = 0.3, y(x) ~= 0.08585.

 

[Syringer]

Originally posted by: Vegitto

Originally posted by: chuckywang

Originally posted by: Vegitto
You guys are weird. I think my solution is much better, although unfinished. (I'm only 15, though, and this should exceed any knowledge I have .)

y = (x^2)(sqrt(1-(x^2)))
y^2 = (x^4)(1-(x^2))
y^2 = x^4 - x^6
y = sqrt(x^4 - x^6)

My TI-83 thinks it's correct, but I can't simplify it any further .
Can you take it from here?

Great, so you didn't take a single derivative and we are, like Maxine Nightingale says, right back where we started from.

So x^4 - x^6 can't be simplified? My math world is collapsing!

x^4-x^6
= x^4 (1-x^2)
sqrt of that = x^2 *sqrt(1-x^2) = original problem