Respuesta :
Given:
The height of a golf ball is represented by the equation:
[tex]y=x-0.04x^2[/tex]
To find:
The maximum height of of Anna's golf ball.
Solution:
We have,
[tex]y=x-0.04x^2[/tex]
Differentiate with respect to x.
[tex]y'=1-0.04(2x)[/tex]
[tex]y'=1-0.08x[/tex]
For critical values, [tex]y'=0[/tex].
[tex]1-0.08x=0[/tex]
[tex]-0.08x=-1[/tex]
[tex]x=\dfrac{-1}{-0.08}[/tex]
[tex]x=12.5[/tex]
Differentiate y' with respect to x.
[tex]y''=(0)-0.08(1)[/tex]
[tex]y''=-0.08[/tex]
Since double derivative is negative, the function is maximum at [tex]x=12.5[/tex].
Substitute [tex]x=12.5[/tex] in the given equation to get the maximum height.
[tex]y=(12.5)-0.04(12.5)^2[/tex]
[tex]y=12.5-0.04(156.25)[/tex]
[tex]y=12.5-6.25[/tex]
[tex]y=6.25[/tex]
Therefore, the maximum height of of Anna's golf ball is 6.25 units.
