Question 1197165


The cost of production of an item is represented with the following equation: 

{{{C(x) = 7x + 10}}}

The revenue function for this item was determined to be: 

{{{R(x) = - 2x^2 + 59x }}}

What is the maximum amount of profit that can be made at the point where the number of items is the greatest to maximize profit?


Profit is revenue minus cost.  This means there is a function, {{{P(x)}}}, that is profit. 
 
{{{P(x) = R(x) - C(x)}}}

{{{P(x) =- 2x^2 + 59x  - (7x + 10)}}}

{{{P(x) =- 2x^2 + 59x  - 7x -10}}}

{{{P(x) =-2x^2 + 52x - 10}}}

the maximum amount of profit that can be made at the vertex (parabola is opening down)

{{{P(x) =-2x^2 + 52x - 10}}}..........write in vertex form

{{{P(x) =(-2x^2 + 52x) - 10}}}......complete square

{{{P(x) =-2(x^2 -26x+b^2)-(-2b^2) - 10}}}............ coefficient of {{{x}}} is {{{26}}}, so {{{b=13}}}

{{{P(x) =-2(x^2 -26x+13^2)+2*13^2- 10}}}

{{{P(x) =-2(x -13)^2+328}}}

=> vertex is at ({{{13}}},{{{328}}})

 the maximum amount of profit is {{{P(x) =328}}} at {{{x=13}}}