The profit that a vendor makes per day by selling x elephant ears is given by the function P(x)= -0.004x^2+3.2x-200. Find the number of elephant ears that must be sold to maximize profit. To maximize profit elephant ears must be sold

The number of elephant ears that must be sold to maximize profit is 400.

Step-by-step explanation:

Given that,

The profit that a vendor makes per day is given by

P(x)= - 0.004x² +3.2 x -200

where x is number of elephant ears.

P(x)= - 0.004x² +3.2 x -200

Differentiating with respect to x

P'(x)= - 0.008x+3.2

Again differentiating with respect to x

P''(x) = -0.008

For maximum or minimum P'(x)=0

- 0.008x+3.2=0

⇒0.008x=3.2

⇒ x = 400

Since at x=400, P''(x)<0, the profit is maximize.

P(400) = -0.004×400²+3.2×400-200

          =440

The number of elephant ears that must be sold to maximize profit is 400.

109 is the nearest whole number/final answer! : )