Write function about area of rectangle. Height is x+2 and length is 20-2x. Show that fubction fits the definition of a quadratix function. Thenx ;)

4 answers

area = (x+2)(20-2x)
= 20x - 2x^2 + 40 -4x
= -2x^2 + 16x + 40
which is a quadratic function because of the -2x^2 term
What would be the domain and range of this equation oh great lord reiny
Or anyone else
as with all polynomials, the domain is (-∞,∞)

area = 72-2(x-4)^2

You can see that its maximum value is at x=4, since then (x-4)=0 and nothing is subtracted from 72.

So, the range is (-∞,72]