How to use multi-variable functions as inputs.

This is what I am trying to do

f = @(x1,x2,x3)x.^2+3.*x2.^2+4.*x3.^2-2.*x1.*x2+5.*x1+3.*x2+2.*x3;
ezplot(f)
fminsearch(f,[0,0,0])

I keep getting error saying not enough input arguments for fminsearch and I want to plot that function but not sure how?

Answer 1

[Star Strider]

You need to parameterise your functions so that x(1)=x1, x(2)=x2, and so forth. Then your function is: f=@(x)... with the appropriate expression following it.

Then use fsolve if you have the Optimization Toolbox.