how do I evaluate the value of an expression?

x = [-2:0.01:1];
f = (x.^2) -x +1 - (exp(-x));
x1 = -1.9;
f(x1)

this gives me the error:

Array indices must be positive integers or logical values

How can I manage to extract the right value of f at x1?

thanks!

Answer 1

[Star Strider]

Try this:

f = @(x) (x.^2) -x +1 - (exp(-x));
x1 = -1.9;
fx1 =  f(x1)

creating an anonymous function and producing:

fx1 = 
        -0.175894442279269

See the documentation section on Anonymous Functions for details.

[Matteo Masto]

thank you very much!!

[Star Strider]

As always, my pleasure!

Answer 2

[Joshua Hodson]

6x4>32-3