Hey guys, apparently it's incorrect to put the absolute value signs, can anybody confirm this? Or support it? I know it works out mathematically but I was told it's still wrong.

NoSash

2006-02-08 03:51:39

yeah it all makes sense, thanks guys

mathsyperson

2006-02-08 03:37:19

All of the above is correct. They've hidden it with lots of unnecessary complications, but what they're basically doing is saying that as x² = (-x)², then x = -x, even though it doesn't.

krassi_holmz

2006-02-07 20:00:30

Yep.

kempos

2006-02-07 19:47:56

step 5. there you should have absolute value.

krassi_holmz

2006-02-07 17:57:01

e.a. 4) (4 - 9/2)^2 = (5 - 9/2)^2 5) |4-9/2|=|5-9/2| 6) |-0.5|=|+0.5| which is OK.

darthradius

2006-02-07 09:58:00

when you take the square root, you need the ± which gives you a few different combinations...this "proof" just uses one combination that does not work.