eq1: (x * y) - (2 * x) - (4 * y) + 4 = 0
O_1 = Center(eq1)
O = Intersect(xAxis, yAxis)
u = Vector(O_1, O)
eq1' = Translate(eq1, u)
g = SecondAxis(eq1')
k = Slope(g)
β: atand(k)
α: 90° - β
f = FirstAxis(eq1')
eq1'_{1} = Rotate(eq1', α)