How to form an array from -10 to 10 to substitute into a polynomial as values of x and have the evaluated values as the output

My attempt is as follows:

 function scriptStart

 for x = (-10:10)

     y = x.^3 - 3*x.^2 + 5*x*sin(pi(x/4) - 5*(pi/4)) + 3;

 end

All I get as outputs is an error, which changes every time i try to make a change to the above.

 Error using pi
 Too many input arguments.

 Error in scriptStart (line 4)
    y = x.^3 - 3*x.^2 + 5*x*sin(pi(x/4) - 5*(pi/4)) + 3;

This is my current and mostr persistant error. I've looked and looked and i cant find the solution to my specific problem, presumably because it is so simple nobody has had to ask. So let me be the first.

I need to create an array for the x variable from x = −10 to x = 10, with appropriate spacing. Then use a for loop to evaluate the values of F according to equation

 y = x^3 - 3*x^2 + 5*x*sin(pi(x/4) - 5*(pi/4)) + 3;

Any and all help appreciated,

Thank you

Answer 1

[Birdman]

A symbolic approach(requires Symbolic Toolbox)

syms x
y = x.^3 - 3*x.^2 + 5*x*sin(pi*(x/4) - 5*(pi/4)) + 3;
yVal=vpa(subs(y,x,-10:10),4)

[Liam Wiltshire]

Fab, thank you very much this worked a charm.