% Calculate change in surface area of a sphere given a change in radius

% Gather input
radius= input('Enter radius [mi]: ');
delta_r_in= input('Enter change in radius [in]: ');

% Perform calculation
area= 4*pi*radius^2;
delta_r_ft= delta_r_in/12;
delta_r_mi= delta_r_ft/5280;
new_radius = radius + delta_r_mi;
new_area = 4*pi*new_radius^2;
delta_area = new_area - area;

% Display output
disp('Original surface area [mi^2]: ')
disp(area)
disp('Increase in surface area [mi^2]: ')
disp(delta_area)
