Major error in Barron's Math II 8th edition:

lJmYEA
Mon, 18 Jan 2010 11:38:59 +0000

Page 123, part B of example #1:

(4x^2) + (4y^2) - 12x - 20y - 2 = 0

You’re supposed to complete the square to find the equation of the circle and here’s how they do it:

(x^2 - 3x + 9/4) + (y^2 - 5y + 25/4) - 2/4 = 9/4 + 25/4

(note the 2/4)

and get:

( x - 3/2)^2 + ( y - 5/2)^2 = 9

My question is: shouldn’t the costant ‘2’ of the original equation be carried out the other side of the equal sign which would change the answer completely? And why is it 2/4 instead of just 2?

…or is this just another of Barron’s typos??