Question 512807
{{{ C(x) = 2x^2 - 32x + 720 }}}
The minimum, or lowest cost is the vertex V(x,y)
The formula for the x-coordinate is:
{{{ -b/(2a) }}}
when the equation is in the form
{{{ ax^2 + bx + c }}}
{{{ a = 2 }}}
{{{ b = -32 }}}
{{{ -b/(2a) = -(-32)/(2*2) }}}
{{{ -b/(2a) = 32/4 }}}
{{{ -b/(2a) = 8 }}}
Now plug this into the equation to find {{{C(8) }}}
{{{ C(8) = 592 }}}
The lowest cost is $592
You can check this by plugging {{{ x = 7.9 }}}
and {{{ x = 8.1 }}} into the equation and seeing
if they are both less than {{{ 592 }}}