Posted by avincent on .
w=Cr^2 solve for r

Alegebra 
DrBob222,
w = Cr^2
w = C/r^2
wr^2 = C
r^2 = C/w
r = +/ sqrt (C/w)
Check mu work. 
Alegebra 
avincent,
i came up with r=sqrt of C/w
what is the +/ for ? could it be either positive or negative? 
Alegebra 
DrBob222,
ANYTIME you take the square root of something, you get a + or . Let me show you why.
Take the square root of 4. That is 2. Now if we multiply +2 x +2 we get +4. BUT if we multiply 2 x 2 we also get +4. So the square root of 4 is +/ 2. Same with anything else because a minus number x a minus number = a + number.