Sketch each parabola. La $x$-intercepts. a) $y=(x+2)(x-4)$

Step 1 ：Find the x-intercepts by setting y = 0 and solving for x: \(y = (x - 4)(x + 2)\)

Step 2 ：\(x\)-intercepts: \(x = -2, 4\)

Step 3 ：Find the axis of symmetry as the midpoint between the x-intercepts: \(x = \frac{-2 + 4}{2} = 1\)

Step 4 ：Find the vertex by plugging the axis of symmetry into the equation: \(y = (1 - 4)(1 + 2) = -9\)

Step 5 ：Vertex: \((1, -9)\)

Step 6 ：\(\boxed{\text{The parabola has x-intercepts at -2 and 4, a vertex at (1, -9), and an axis of symmetry at x = 1.}}\)