Plotting in Matlab with Range for Independent Variable

I'm creating a simple model of a spring-mass system and am trying to plot the amplitude as a function of the spring constant. I'm using the equation natural frequency = s=sqrt(k/m), where k is the spring constant and m is the mass. Also, amplitude = sqrt(natural frequency^2 + initial position^2)/natural frequency.

I'm not getting any errors, but I'm getting an empty plot and an "answer" in the command window that I do not need.

The code I have so far is:

function A = amp(k)
g = 4; %initial position
m = 2; %mass
k = 0.05:0.1:0.3; %range of spring constant
A = sqrt((sqrt(k/m)).^2+16)/(sqrt(k/m));
figure(3)
plot(k,A);
end

I'd appreciate it if someone could take a closer look at the code.

Answer 1

[Star Strider]

You need to use element-wise operations in the division:

A = sqrt((sqrt(k/m)).^2+16)./(sqrt(k/m));
                           ↑

Try this:

g = 4; %initial position
m = 2; %mass
k = 0.05:0.01:0.3; %range of spring constant
A = sqrt((sqrt(k/m)).^2+16)./(sqrt(k/m));
figure(3)
plot(k,A);

I also increased the number of elements in ‘k’.