- #1

jk4

I know all the basic rules of significant figures, however I'm just curious about how it should be applied in equations. For example say I was trying to solve:

[tex]\sqrt{1-\frac{(0.99c)^{2}}{c^{2}}}[/tex]

I get [tex]0.99^{2} = 0.9801[/tex] which I would then round to 0.98. Then:

1 - 0.98 = 0.02

So now, the addition/subtraction significant figure rules say that I only take 2 digits past the decimal place which will give me 0.02 of course, which is very different from 0.020

so am I now supposed to use only 1 significant figure??? Or do I solve the entire equation before applying significant figures?

If the later is the case then wouldn't this present big problems because there are usually several different ways to find an answer in physics so different people with different methods would get different answers....