The profit (in thousands of dollars) of a company is represented as P=−5x2+1,000x+5,000

, where P represents the profit and x represents the amount spent on marketing (in thousands of dollars). How much spending in the thousands will be directed toward marketing to achieve the maximum profit?

1 answer

The profit function given is

\[ P = -5x^2 + 1000x + 5000 \]

This is a quadratic function in the standard form \( P = ax^2 + bx + c \), where \( a = -5 \), \( b = 1000 \), and \( c = 5000 \).

Since the coefficient of \( x^2 \) (which is \( a \)) is negative, this function opens downwards, indicating that there is a maximum profit.

To find the value of \( x \) that maximizes \( P \), we can use the vertex formula for a quadratic equation. The \( x \)-coordinate of the vertex, where the maximum occurs, is given by:

\[ x = -\frac{b}{2a} \]

Substituting \( a = -5 \) and \( b = 1000 \) into the formula:

\[ x = -\frac{1000}{2 \times -5} = -\frac{1000}{-10} = 100 \]

Thus, the amount spent on marketing to achieve maximum profit is \( x = 100 \) (in thousands of dollars).

Therefore, the optimal marketing spending to achieve maximum profit is

\[ \boxed{100} \] (which corresponds to $100,000).