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Mathematics 13 Online
OpenStudy (zzr0ck3r):

what is wrong here?

OpenStudy (zzr0ck3r):

\[-1=(-1)^1 = (-1)^{\frac{2}{2}}=\sqrt{ (-1)^2}=\sqrt{1} = 1\]

OpenStudy (zzr0ck3r):

this seems to be saying there is an order in which we evaluate the numerator and denominator in fractional exponents

OpenStudy (luigi0210):

\[\sqrt{x}=\pm x\]

OpenStudy (zzr0ck3r):

still, then -1 = -1 and -1=1

OpenStudy (zzr0ck3r):

I know something like this was asked here a while ago, but I don't think anyone got to the bottom of it.

OpenStudy (zzr0ck3r):

I guess it would then be -1 = -1 or -1 = 1, and this is of course true, but still....

HanAkoSolo (jamierox4ev3r):

does this have something to do with absolute value or something?

OpenStudy (zzr0ck3r):

yeah

hartnn (hartnn):

\(\sqrt{x^2}= |x|\)

OpenStudy (zzr0ck3r):

correct, even that suggest an order

hartnn (hartnn):

what is |x| when x is negative ? -x, right ??

OpenStudy (zzr0ck3r):

yes still, if we define |x| = sqrt(x^2) = x^(2/2) (which I don't think we do) it still suggest an order

OpenStudy (zzr0ck3r):

there has always just been some weirdness with the notations...

OpenStudy (zzr0ck3r):

The way my book defines |x| has nothing to do with exponents, its the piece wise definition that is real, that other one is just to make that a little more simple ...or something I don't know why people use it.

hartnn (hartnn):

\((-1)^{\dfrac{2}{2}}=(\sqrt{-1})^2\)

OpenStudy (zzr0ck3r):

right, again order....

hartnn (hartnn):

yes, the order is important, square root is evaluated first....

OpenStudy (zzr0ck3r):

so, what are the real definitions for this stuff, I never here anyone talk about fractional exponents having order.

OpenStudy (zzr0ck3r):

so they are not really fractions in the exponent, or they would not have order, since exponents are repeated multiplication....bah this is gonna bug me:)

OpenStudy (zzr0ck3r):

so maybe there is order when the fractions are not in there reduced forms

OpenStudy (zzr0ck3r):

so if (top part of fraction, bottom part of fraction) = 1, we have no order:)

OpenStudy (zzr0ck3r):

whiskey and math might not be the best combo:)

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