Answer:
31 trees per acre will maximize the harvest
Step-by-step explanation:
Given
[tex]Plant \to 55[/tex] trees/acre
[tex]Yield \to 25[/tex] bushels
[tex]x \to trees[/tex]
Required
Number of trees to maximize harvest
From the question, we understand that:
Yield will decrease by 4 i.e. 25 - 4x
For every additional tree planted, i.e. 55 + x
So, the function is:
[tex]F(x) = (25- 4x)*(55+x)[/tex]
Open bracket
[tex]F(x) = 25 * 55 -4x * 55 + 25 * x -4x*x[/tex]
[tex]F(x) = 1375 - 220x + 25x -4x^2[/tex]
[tex]F(x) = 1375 -195x -4x^2[/tex]
Rewrite as:
[tex]F(x) = -4x^2 -195x +1375[/tex]
The maximum of a quadratic function is calculated as:
[tex]Max = -\frac{b}{2a}[/tex]
In the above equation:
[tex]a = -4; b =-195; c = 1375[/tex]
So:
[tex]x = -\frac{-195}{2 * -4}[/tex]
[tex]x = -\frac{195}{8}[/tex]
[tex]x = -24.375[/tex]
Recall that the number of trees to be planted is: 55 + x
So, we have:
[tex]Trees = 55+x[/tex]
[tex]Trees = 55-24.375[/tex]
[tex]Trees = 30.625[/tex]
Approximate
[tex]Trees = 31[/tex]
