How to solve this problem: Not enough input arguments. Nonlinear equations, Vegstein

function [ root, k ] = veg(f,a,b)

e = 0.00001;

x0 = a;

x1 = b;

xn = x1 - (f(x1)*(x1-x0)/(f(x1)-f(x0)));

k = 1;

while (abs(x1-xn)>e)

k = k+1;

x0 = x1;

x1 = xn;

xn = x1 - (f(x1)*(x1-x0)/(f(x1)-f(x0)));

end

root = xn;

end

[x1f1_vegstein,k] = veg(f1,1.4,1.8);

error1 = abs((abs(x1f1_vegstein)-abs(x1f1))/x1f1);

table(x1f1_vegstein,k,error1)

function f = f1(x1)

f = 2*x1.^4+8*x1.^3-18*x1.^2-1;

end

Not enough input arguments.

Error in f1 (line 2)

f = 2*x1.^4+8*x1.^3-18*x1.^2-1;

Error in lr6 (line 77)

[x1f1_vegstein,k] = veg(f1,1.4,1.8);

Answer 1

[Govind Narayan Sahu]

use @ symbol with f1 as given below:

[x1f1_vegstein,k] = veg(@f1,1.4,1.8);

After that you will get the root but also get the error since you have not created the variable x1f1. Please check.