2022-05-19 17:10:22 +0200 answered a question How to recompute symbolic expression Yes thank you, this is a convenient solution. 2022-05-19 17:09:41 +0200 marked best answer How to recompute symbolic expression I have a symbolic expression with symbolic evaluation. After I whand to eval the function to it's expression but it doent work : var("x, omega, t") u = function('u')(x) eq = u(x=1) == cos(omega*t) eq.show() u(x) = e^(2*t*x) eq.show  𝑢(1)=cos(𝜔𝑡) 𝑢(1)=cos(𝜔𝑡) But now if I create again eq equation, this time it works. eq2 = u(x=1) == cos(omega*t) eq2.show()  𝑒(2𝑡)=cos(𝜔𝑡) Is-it a function recompute to replace easily function by it value ? The working solution I found isn't practical : var("x, omega, t") uf = function('u')(x) eq = uf(x=1) == cos(omega*t) eq.show() u2(x) = e^(2*t*x) eq.substitute_function(u, u2).show()  I look on subs() and substitute_function() but their behaviour isn't convenient for this case. 2022-05-19 17:09:41 +0200 received badge ● Scholar (source) 2022-05-18 18:03:54 +0200 asked a question How to recompute symbolic expression How to recompute symbolic expression I have a symbolic expression with symbolic evaluation. After I whand to eval the f