Suppose a granola bar company estimates that its monthly cost is [tex]C(x) = 500x^2 + 400x[/tex] and its monthly revenue is [tex]R(x) = -0.6x^3 + 800x^2 - 300x + 600[/tex], where [tex]x[/tex] is in thousands of granola bars sold. The profit is the difference between the revenue and the cost.

What is the profit function, [tex]P(x)[/tex]?

A. [tex]P(x) = 0.6x^3 - 300x^2 + 700x - 600[/tex]
B. [tex]P(x) = -0.6x^3 + 300x^2 - 700x + 600[/tex]
C. [tex]P(x) = -0.6x^3 + 1300x^2 + 100x + 600[/tex]
D. [tex]P(x) = 0.6x^3 + 300x^2 - 700x + 600[/tex]



Answer :

To determine the profit function, [tex]\( P(x) \)[/tex], we need to subtract the cost function, [tex]\( C(x) \)[/tex], from the revenue function, [tex]\( R(x) \)[/tex]. Given the cost function and revenue function:

[tex]\[ C(x) = 500x^2 + 400x \][/tex]
[tex]\[ R(x) = -0.6x^3 + 800x^2 - 300x + 600 \][/tex]

The profit function [tex]\( P(x) \)[/tex] is defined as:

[tex]\[ P(x) = R(x) - C(x) \][/tex]

Substitute the given functions into the equation:

[tex]\[ P(x) = (-0.6x^3 + 800x^2 - 300x + 600) - (500x^2 + 400x) \][/tex]

Now, distribute the negative sign and combine like terms:

[tex]\[ P(x) = -0.6x^3 + 800x^2 - 300x + 600 - 500x^2 - 400x \][/tex]

Combine the [tex]\( x^2 \)[/tex] and [tex]\( x \)[/tex] terms:

[tex]\[ P(x) = -0.6x^3 + (800x^2 - 500x^2) + (-300x - 400x) + 600 \][/tex]

Simplify further:

[tex]\[ P(x) = -0.6x^3 + 300x^2 - 700x + 600 \][/tex]

So, the correct profit function is:

[tex]\[ P(x) = -0.6x^3 + 300x^2 - 700x + 600 \][/tex]

Hence, the correct answer is:

B. [tex]\( P(x) = -0.6x^3 + 300x^2 - 700x + 600 \)[/tex]