function that calculates volume and surface area of a sphere

Write a function that calculates and returns the volume and surface area of a sphere V and S respectively with radius R. The function should check the input value of R (real and positive). If the user enters more than one value R, your function should automatically plot volume V as a function of radius R as well as surface area S as a function of radius R. Assume that R is in meters. Use subplot for your figure.

[Image Analyst]

Yelbatyr, your post is not an Answer to Desperado's 6 year old question, it's basically just a restatement of the original question. The pi symbol is "pi", so if you would have posted a real answer would have included lines like

volume = (4/3) * pi * r.^3;
surfaceArea = 4 * pi * r .^ 2;

Now you just need to add the function line.

How do I get help on homework questions on MATLAB Answers? - MATLAB Answers - MATLAB Central

[Walter Roberson]

Hints:

In MATLAB, the numeric approximation of π is pi()

In MATLAB, there is no implied multiplication. You must use a multiplication operator

Answer 1

[TED MOSBY]

Hi,

To calculate and return the volume and surface area of a sphere, while also plotting these quantities if multiple radii are provided, I wrote an example MATLAB function as follows:

% call the function 
[volume, surfaceArea] = sphereMetrics([1, 2, 3, 4]); 
function [V, S] = sphereMetrics(R) 
    % sphereMetrics calculates the volume and surface area of a sphere. 
    % Inputs: 
    %   R - Radius of the sphere (can be a scalar or vector) 
    % Outputs: 
    %   V - Volume of the sphere(s) 
    %   S - Surface area of the sphere(s) 
    
    % Check if R is a real positive number 
    if any(~isreal(R) | R <= 0) 
        error('Radius must be a real positive number.'); 
    end 
    
    % Calculate volume and surface area 
    V = (4/3) * pi * R.^3; 
    S = 4 * pi * R.^2; 
    
    % If more than one radius is provided, plot the results 
    if numel(R) > 1 
        figure; 
        % Plot Volume as a function of Radius 
        subplot(2, 1, 1); 
        plot(R, V, 'b-o'); 
        xlabel('Radius (m)'); 
        ylabel('Volume (m^3)'); 
        title('Volume of Sphere as a Function of Radius'); 
        grid on; 
        
        % Plot Surface Area as a function of Radius 
        subplot(2, 1, 2); 
        plot(R, S, 'r-o'); 
        xlabel('Radius (m)'); 
        ylabel('Surface Area (m^2)'); 
        title('Surface Area of Sphere as a Function of Radius'); 
        grid on; 
    end 
end 

Hope this resolves your query!