square root of -1, wuts up with it.

Seriously. I don't get it.

Whats so special about the square root of -1? its supposed to be a "magical" number or something...

but then, no negative number can have a square root.

because it takes a positive and a negative to make a negative.

EX:

-49.

7x7 = 49
-7x-7 = 49

and squaring something means multiplying it by the same number, so you can't have square roots of negative numbers.

and wut about that -1?

i is the sqaure root of -1. it is in a nother level of math, don't worry too much about it untill you are halfway through algebra 2 and in precalc or AP calc. just remember that it can be though of as a variable to an extent and simplified(i^2 = -1)

pretty much in all, i is an abstract term, it is an "imaginary number" meaning that it does not exist in our standard system of numbers, don't think though that it doesn't have its uses though, imaginary numbers are more than tools for empirism they actually have somewhat practical uses, most involving calculations with electrical currents involved.

It's special because the square root of negative one is equal to an imaginary number, this number is 1i. When you square 1i you get negative one. To square it you multiply "a"(which in this case is the one out front) times "i" squared, "i" squared is equal to negative one. So 1 x -1= -1.

strange, i don't get it, but then, i'm not halfway through algebra 2 and blah blah blah.

Originally Posted by PhOeNiX~ArChEr

strange, i don't get it, but then, i'm not halfway through algebra 2 and blah blah blah.

disregard what brolik said, the way he worded it was weird and I think he left out a square root symbol or something like that. EDIT: the syntax he said it in was weird that was all, he was technicall correct.

essentially i is set so that i^2=-1. This was made so people could go farther in math because they were limited, in short it was a way around not being able to take the sqrt of negative numbers, simlply factore out a root -1 and replace it with i and continue with the problem. it is nothing hard, it is pretty much just substitution.

here is an example

x^2+9=0
X^2=-9
x=+/- sqrt (-9)
x= +/- sqrt(9)*sqrt(-1)
x= +/- 3i

in all don't worry about it until you learn it in that class there isn't that much to it.

This seems like Temple of Knowledge stuff to me. Moved.

I remember imaginary numbers. Learned about those my Sophomore year. Well, in 7th grade actaully, but that's just because I asked. No teacher taught it to me as a part of the curriculum until Algebra 3-4.

If zelink didn't explain it well enough, I'd suggest asking your math teacher or just waiting until you learn it.

Consider i to be an indefinable variable whose square is -1.

For example, if you multiply 7i by 8i, you will get -56 because 7 times 8 is 56 and i times i is -1. It's less complicated than it looks.

If we didn't have i (wow, that vb code looks weird), we could not describe a lot of what happens in the world. We understand the physics, we just needed to change the MATH to agree with it. Math is a tool. Physics is a SCIENCE ;0)

Put into better words--Physics is math with attitude.

ok, so the sqareroot of -1 walks into a bar. he walks up to the first girl he sees and askes her for her phone number. she promptly says "get real."

i love that joke.

anywho, you cannot square something and have the answer negative.
because whenever you sqare something the answer is positive.

like you said, sqareing something is multiplying by itself, so you can't have -7 * 7 be sqareing.

and, as BBD said, i(slanted) is used in physics alot. because sometimes we need to take the sqare root of a negative number.

-1 X -1= -1


Negative +/x/- Negative = Negative
Negative +/x/- Positive = Negative
Positive +/x/- Positive = Positive

I think that is what you are asking, Phoenix~Archer.

Whoa. . .I just learned this yesterday!

The square root of -1 does not exist - it only is used as a theoretical "object" for engineering and computers.

Originally Posted by Quest_For_Zelda

The square root of -1 does not exist - it only is used as a theoretical "object" for engineering and computers.

no it exists just not by standard understanding, it is comonly used for calulating electric currencies.

Originally Posted by PrincessTetra7

-1 X -1= -1


Negative +/x/- Negative = Negative
Negative +/x/- Positive = Negative
Positive +/x/- Positive = Positive

What are you talking about?
-1 times -1 equals 1
-1 times (+)1 equals -1
(+)1 times (+)1 equals 1

That goes for all, - x - = +, - x + = -, + x + = +

Whenever you're timing a negative number, it has to go down, not up. WHen dividing a negative, you should go up

EX:

-2 x 7 = 14
-2 / 7 = -14

If you want to find out how you're going to find what the square root of this -1 is, you're going to have to square the number first.

-1 x -1 = 1

And it concludes that the square root of -1, is 1. There's really no 'magic' in it.

Originally Posted by The half-a-bee

What are you talking about?
-1 times -1 equals 1
-1 times (+)1 equals -1
(+)1 times (+)1 equals 1

That goes for all, - x - = +, - x + = -, + x + = +

Wait. . .I only learned multiplying. . .My math teacher always leaves out the important stuff. All this math is giving me a headache. *head throbs*

Originally Posted by Kagun

Whenever you're timing a negative number, it has to go down, not up. WHen dividing a negative, you should go up

EX:

-2 x 7 = 14
-2 / 7 = -14

If you want to find out how you're going to find what the square root of this -1 is, you're going to have to square the number first.

-1 x -1 = 1

And it concludes that the square root of -1, is 1. There's really no 'magic' in it.

What?

When multiplying or dividing with one negative and one positive, the answer is always negative.
-2 x 7= -14
And when dividing with negatives, you divide as normal.
-2 / 7 = -0.286 (rounded to three digits)
If two negatives or two positives are multiplied or divided, the answer is always positive.

The square root of -1 is i. (You're right, BBD. It does look weird.) It's called an imaginary number. You don't multiply -1 by itself and then square it. Otherwise, the square root of 4 would be worked out like this-
4 x 4 = 16
Square root of 16= 4
Doesn't make sense. The square root (the two numbers that multiply together to make x) of 4 is 2 (2 x 2=4).
And i x i = -1.

-IANVS

Originally Posted by Kagun

If you want to find out how you're going to find what the square root of this -1 is, you're going to have to square the number first.

The square root of a number is what two equal, alike numbers you must multiply with each other to get the number.

the squar root of 16 is 4, because 4 x 4 = 15, as janus said.

And, since only - x + = -, you can't find two equla, alike numbers that give -1.

And, one thing more.

-2 x 7 is not 14, it is -14

-2 / 7 is not -14, it is -o,2.... something.

try it on your comp calculators, try multiplying two negative numbers(-2 and -3, for eksample), try it Kagun.

Edit after what janus said: ... Crud.

Yea, I meant 16, was a very bad typo.

Somehow, I think you meant 4 x 4 = 16, not 15. :cool:

-IANVS

Oh, it's just that on negative, when you add, you go backwards, not forwards. The math world is so annoying.

I don't mean this offensively, but kagun I would assume that your current lavel of math does not even remotely cover this, I beleive that you are 9 if I am not mistakem, that would place you in about the 4th grade, the first time most people are introduced to this in in the 11th grade(though it is a very basic concept and one could very easily learn and understand it earlier, I took algebra II in the 9th grade for example because I skipped two grades in math). Same applies to PT7. I am not targeting any one person, but if you do not understand what is being asked do not try to help them.

EDIT:what your logic was was that -1 ^2=1, which is correct, from there you could say that the sqrt of 1 is -1(as well as positive 1) as was said your logic is a bit off(you do the inverse essentially) but your a bit young to be messing with square roots and the like so you have nothing to worry about.