Plotting an Unknown Variable Exponent?

Hello, I am trying to figure out how to solve for an unknown variable exponent via graphing. Using the equation:

F = P^-m

I am trying to solve for the value of m given a set of F and P values. I am very new to Matlab and really have no idea how to solve this problem. I know how to set up the column vectors with the data I have, mainly F and P, but do not know how to graph this equation and solve for m. Any input would be appreciated. Thank you.

Ashley

Answer 1

[the cyclist]

I assume this is homework.

Here's a hint: Think about taking the logarithm of each side of this equation, and think about plotting the result.

[Ashley]

Hello, Yes, I know, I actually did it that way by taking the logs and solving for m, but my professor said there's another way to do it using a power function. This is where I am getting confused! Thank you for your input.

Ashley

Answer 2

[Image Analyst]

Try this little demo and see where the curves (formed using different m values) cross the flat line which is a constant F value:

P = 0 : 0.01 : .4;
F = 900 * ones(1, length(P));
plot(P, F);
hold on;
% Enlarge figure to full screen.
set(gcf, 'units','normalized','outerposition',[0 0 1 1]);

% Plot for various values of m.
for m = 1:.5:2
  y = P .^ (-m);
  plot(P, y, 'b+-');
end