Symbolic expressions inside of array

syms x

f(x) = x^2;

g(x) = x^3;

a = [f,g];

Imagine I have a code like this, and I wish to evaluate only f for a certain value, but not bring outside of the array. How can I do this? For instance, if now ask for a(3), matlab will output [9,27]. However, I want only want 9.

Answer 1

[David Hill]

syms x y
f = x^2;
g = y^3;
a = [f,g];
subs(a,x,3);

[Bram van Eijnatten]

You answer gives me the output [9, y^3], whereas I want merely 9

[Bram van Eijnatten]

Never mind subs(a(1),x,3) gives the answer, thanks!