# Error with 'loadstring' finding even powers of negative numbers

Hello,
I ran into an issue recently where when you find a negative number to the power of 2 (in example), the result will be negative. Here is my example to prove it:

``````function setup()
for i = -10,10 do
local computedNormally = i^2
local computedDynamically = loadstring("return "..i.."^2")()
print("i: "..i.."\
Normally computed math: "..computedNormally.."\
Computed using 'loadstring': "..computedDynamically)
end
end
``````

I’m doing a temporary fix by simply making it positive if the input is negative.

Thank you!

I don’t know why… but you can use `math.pow` if you need.

@Zoyt adding parenthesis around i solves it for loadstring. But you are right, it is annoying. On the other hand, the notation -1^2 is ambiguous:is it (-1)^2 or -(1^2)?

Actually all of this is correct. A negative number such as -5^2 is -25. You need to look up order of operation for math functions. The ^ (power) has a higher order than - (minus). So in the example -5^2 means it takes 5^2 first making it 25. Then the - comes next making it -25. The () have an even higher order then ^, so in (-5)^2, it makes 5 negative before it squares it, making the answer 25.

@dave1707 - I thought of that right as I went offline. You’re right. I’ll just put parenthesis around it.
Thanks!

See, maths is important!

@Andrew_Stacey - Remember, eats, shoots, and leaves. (It’s math’s.)
But thanks.

@Zoyt. I wrote:

“maths is important”

No apostrophe needed there. Where do you see the need for one?

@Andrew_Stacey, I agree there is no need for one, but couldn’t it be written as “math’s important”?

@JakAttak But then it would be “maths’s important” which is just weird.

@Andrew_Stacey You don’t put an S after the apostrophe if the word ended with S before, but you pronounce it with an S on the end. It would be maths’. Still looks kinda weird, though…

@SkyTheCoder That’s the rule for the possessive pronoun. This is a contractive apostrophe. I don’t know if one would ever contract a word ending in ‘s’ with ‘is’ as it doesn’t sound any different.

@Andrew_Stacey, wouldn’t it be math is important and not maths is important in the first place? Or if it were maths, shouldn’t it be maths are important?

@JakAttak Both `math` (US) and `maths` (UK) are abbreviations for `mathematics` which is almost always used as a singular noun. So whether you are American and say `math is important` or British and say `maths is important`, the verb will be the same in either phrase as both are abbreviated forms of `mathematics is important`.

(For a word to compare with, consider `dynamics`. You can say `the dynamics of the machine were complicated` or `dynamics is an important topic in physics`. The word `mathematics` is almost always used in the second sense, not the first.)

@Andrew_Stacey - That makes more sense. You were using the UK abbreviation, I assume?

@Zoyt, well, I am British, after all.