> Can someone tell me why x1+5*x2-sqrt(2*x3)=1 is a > linear equation? For I check the definition of a > linear equation:"All variables only to the first > power and do not appear", and in this case the power > of variable x3 is 1/2, not meeting the definition, > but why is this equation still be regarded as a > linear equation? Thanks.
I would like to see the source information. Suspect a typo: might the right-hand parenthesis be misplaced? If so, then perhaps the intended expression was: x1 + 5*x2 - sqrt(2)*x3 = 1