> No, that was my example. My function is much more complex. So I need to use
> subs(diff(f,t), {X,t}, (X-value, t-value))
> where X is a vector.
syms t
x = sym('x',[3 1])
f = x(1)^2*t^2 + x(2)^2*t^2 + x(3)^2*t^2
subs(subs(diff(f,t),x,ones(3,1)),t,2)![]()
> subs(diff(f,t), {X,t}, (X-value, t-value))
> where X is a vector.
syms t
x = sym('x',[3 1])
f = x(1)^2*t^2 + x(2)^2*t^2 + x(3)^2*t^2
subs(subs(diff(f,t),x,ones(3,1)),t,2)