Sketch the graph of a quadratic function that has the following key features: Opens downward
Has x intercepts at (-2,0) and (4,0)

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm