Chapter ISG, Problem 9.2STP

To determine

To write functions of area.

Answer to Problem 9.2STP

  $f(t)=\pi (4t^2-4t+1)-18$

Explanation of Solution

Given information:

Area of circle in computer game is $y=\pi r^2-18$

Radius of circle is $r=2t-1$

Formula used:

  $A=\pi r^2$

Where A is the area of circle

r is the radius

Calculation:

Area of circle in computer game, $y=\pi r^2-18$

Radius of circle is, $r=2t-1$

Substituting value of r in the area of circle

  $y=\pi {(2t-1)}^2-18$

On solving,

  $y=\pi {(4t^2-4t+1)}^{}-18$

Let $y=f(t)$ is a function area in t

Then area of circle in t seconds

  $f(t)=\pi (4t^2-4t+1)-18$