[math] square root and absolute values

[t1497f35]

Hi,
See "problem" and "answer" screenshots.

Is the answer correct?

Shouldn't there be absolute value bars surrounding the escaped "y"?

[Bachstelze]

Yes, also around x^3, unless x and y are assumed to be positive.

[t1497f35]

Thanks, oh yes - "x" also needs abs value bars cause after being released both of them have odd powers.
Afaik with positive roots you don't have to put the absolute value bars only when you get out a var with a positive power.
Thus a released x^3 needs absolute bars, but if it was x^4 (or any other even positive number) it doesn't need the bars, correct?

At least this is what this guy (http://www.youtube.com/watch?v=1KPJhXSMFs4) seems to say at the end of the video.

[Bachstelze]

sqrt(x^2) is always |x|. But if x is an even power, then it is always positive and |x| is always equal to x, so the absolute value bars are redundant.

[StephenF]

According to the explanation.

100^2 * 3 = 300
I want my digital dollar.