302 Answers to Exercises and Solutions to Problems
and the points of intersection are (-1, -1) and (0, -1).
4.8. (a) The equivalent real system is
x9-3x$-7x+6=0
y(3x2 - y2 - 7) = 0.A, B, C denote solutions(b) The equivalent real system is
x3 - 3xy2 = 2 + 1
3x2y - y3 = y
which can be written
y2 = (1/3)(x2 - 1 - l/x)y(3x2 - y2 - 1) = 0.4.9. (b) Note that (3~~ - 1)2 - (8~~ - 4x2 - 3x + 3) = x4 - 2x2 + 3x - 2 =
(x - 1)(x + 2)(x2 - x + l), f rom which the sign of this difference is easily
determined.