Answer:
![A(w) = w^2 + 5w - (1)/(8)\pi w^2](https://img.qammunity.org/2021/formulas/mathematics/college/40bkuv42bz8y1bvccdlk3r3fisbagd5r56.png)
Explanation:
A = the area of the region outside the semicircle but inside the rectangle
w = the width of the rectangle or diameter of the semicircle
Since "A" is determined by "w", therefore, "A" is a function of "w" = A(w).
A(w) = (area of rectangle) - (area of semicircle)
![A(w) = (l*w) - ((1)/(2) \pi r^2)](https://img.qammunity.org/2021/formulas/mathematics/college/92envilm2az5u16vosws1a38dioh95dnl6.png)
Where,
lenght of rectangle (l) = w + 5
width of rectangle (w) = w
r = ½*w =
![(w)/(2)](https://img.qammunity.org/2021/formulas/mathematics/high-school/fv5ffu9p7078k6jzg20khxitqixsd9nqay.png)
Plug in the values:
![A(w) = ((w + 5)*w) - ((1)/(2) \pi ((w)/(2))^2)](https://img.qammunity.org/2021/formulas/mathematics/college/fu4ldkl55e4ibwepnjtmc8bw5m2ss79dng.png)
![A(w) = ((w + 5)*w) - ((1)/(2) \pi ((w)/(2))^2)](https://img.qammunity.org/2021/formulas/mathematics/college/fu4ldkl55e4ibwepnjtmc8bw5m2ss79dng.png)
Simplify
![A(w) = (w^2 + 5w) - ((1)/(2) \pi ((w^2)/(4))](https://img.qammunity.org/2021/formulas/mathematics/college/dnwjybdr56f61xn1ser359t3gja63ellpe.png)
![A(w) = w^2 + 5w - (1)/(2)*\pi*(w^2)/(4)* \pi](https://img.qammunity.org/2021/formulas/mathematics/college/9qt2yfohlee4qy4cjjtwjdd2krrzilt991.png)
![A(w) = w^2 + 5w - (1*\pi*w^2)/(2*4)](https://img.qammunity.org/2021/formulas/mathematics/college/pldcwc6qz36jj3xhp6mzfceq4wzilhk6mm.png)
![A(w) = w^2 + 5w - (1*\pi w^2)/(8)](https://img.qammunity.org/2021/formulas/mathematics/college/d9sl229ew04izaso1liss0fguko97i1en0.png)
![A(w) = w^2 + 5w - (1)/(8)\pi w^2](https://img.qammunity.org/2021/formulas/mathematics/college/40bkuv42bz8y1bvccdlk3r3fisbagd5r56.png)