Question

Randy is building a fence at the side of his warehouse. He has 120 m of fencing and plans to use the

Answer 1

Answer:

The width (side perpedicular to the wall of the werehouse):  x = 30 m

The lenght (side parallel to the wall of the werehouse):  y = 60 m

Step-by-step explanation:

x - the width of the fenced area

Randy has 120 m of fencing so for the lenght remain (120-2x) m of fencing:

y = 120 - 2x

Area of the fencing:  A = x•y

A(x) = x•(120 - 2x)

A(x) = -2x² + 120x              ←  quadratic function

The maximum value of quadratic function occurs at:  $x=-\frac b{2a}$

a = -2     b = 120

$x=-\frac b{2a}=-\frac{120}{2\cdot(-2)}=-\frac{120}{-4}=30$

y = 120 - 2•30 = 60