Which of the following is true for y(x) that satisfies the differential equation
\(\frac{dy}{dx}=xy - 1 + x - y;\, y(0)=0:\)
(1) \(y(1) = e^{-\frac{1}{2}}-1\)
(2) \(y(1) = e^{\frac{1}{2}}-e^{\frac{1}{2}}\)
(3) \(y(1) = 1\)
(4) \(y(1) = e^{\frac{1}{2}}-1\)