p(x) = -5x^2 + 400x - 2550
p'(x) = -10x + 400
= 0 for a max of p(x)
10x = 400
x = 40 -----> answer for b)
p(40) = -5(40^2) + 400(40) - 2550 = 5450 -- > a)
for c)
solve
4000 = -5x^2 + 400x - 2550
The profit p(x) of a cosmetics company , in thousands of dollars,is given by p(x)=-5x^2+400x-2550, where x is the amount spent on advertising , in thousands of dollars
a) determine the max profit the company can make
b)Determine the amount spent on advertising that will result in the max profit
c)What amount must be spent on advertising to obtain a profit of at least $4 000 000
3 answers
a. Complete the square.
-5x^2 + 400x - 2550
= -5(x^2 - 80x) - 2550
= -5(x^2 - 80x + 1600 - 1600) - 2550
= -5(x + 40)^2 + 8000 - 2550
= -5(x + 40)^2 + 5450
5450 x 1000 = $5,450,000
b. x = 40
40 x 1000 = $40000
c. Between $22 971 & 57 029
-5x^2 + 400x - 2550
= -5(x^2 - 80x) - 2550
= -5(x^2 - 80x + 1600 - 1600) - 2550
= -5(x + 40)^2 + 8000 - 2550
= -5(x + 40)^2 + 5450
5450 x 1000 = $5,450,000
b. x = 40
40 x 1000 = $40000
c. Between $22 971 & 57 029
The profit of a cosmetics company, P= -5x^2+40x-20