I would like to know how to find the slope for three different line in one graph

I have tried multiple times but I'm unsure what to do. I have attached a photo of my data and codes

Answer 1

[Star Strider]

I have no idea what you want to do.

Try this —

V = [5 10 15];
I1 = [0.00487 0.00964 0.0145];
I2 = [0.00106 0.0021 0.00316];
I3 = [0.0006 0.0012 0.00175];

format short g
R1 = diff(V)/diff(I1)

R1 = 
       1038.3

R2 = diff(V)/diff(I2)

R2 = 
       4761.5

R3 = diff(V)/diff(I3)

R3 = 
       8679.2

format short

figure
plot(I1, V, '.-')
hold on
plot(I2, V, '.-')
plot(I3, V, '.-')
hold off
grid

The resistances are the slopes of the lines. They all appear to be perfectly linear, so diff works here. If they were not, a linear regression would be required to calculalte the slope.

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