# Can Symbolics handle complex numbers?
**URL:** https://discourse.julialang.org/t/can-symbolics-handle-complex-numbers/122753
**Category:** General Usage
**Tags:** question, package, symbolics, complex-numbers
**Created:** [November 18, 2024, 2:51am UTC](https://discourse.julialang.org/t/can-symbolics-handle-complex-numbers/122753 "2024-11-18T02:51:54Z")
**Posts on this page:** 5
**Page:** 1
### Author:  [@ccmejia](https://discourse.julialang.org/u/ccmejia)
#### Post date: [November 18, 2024, 2:51am UTC](https://discourse.julialang.org/t/can-symbolics-handle-complex-numbers/122753/1 "2024-11-18T02:51:54Z")
Hi there!
My code:
```julia
using Symbolics
@variables C_0, C_1, R, T, V, k, R0, g
M = [-2*V*cos(k) - im*g V V*exp(im*k) 0;
V -2*V*cos(k) + im*g 0 V*exp(2*im*k);
0 V 0 -2*V*cos(k)*exp(2*im*k) + V*exp(3*im*k);
V 0 -2*V*cos(k)*exp(im*k) + V*exp(2*im*k) 0]
b = [-R0*V*exp(-im*k); 0; 0; 2*R0*V*exp(-im*k)*cos(k)-R0*V*exp(-2*im*k)]
eqs = M*[C_0, C_1, R, T] + b
symbolic_solve(eqs, [C_0, C_1, R, T])
```
The error message:
> MethodError: Num(::Complex{Num}) is ambiguous. Candidates: Num(val) @ Symbolics [~/.julia/packages/Symbolics/GYV9b/src/num.jl:2](http://localhost:8889/lab/tree/Dropbox/SEMINARS/ascenso_escalafon/~/.julia/packages/Symbolics/GYV9b/src/num.jl#line=1) (::Type{T})(z::Complex) where T\<:Real @ Base complex.jl:44 Possible fix, define Num(::Complex)
What is going on here? How can I solve this?
---
### Author:  [@Oscar\_Smith](https://discourse.julialang.org/u/Oscar_Smith)
#### Post date: [November 18, 2024, 3:29am UTC](https://discourse.julialang.org/t/can-symbolics-handle-complex-numbers/122753/2 "2024-11-18T03:29:08Z")
This isn’t an answer to your issue, but consider using `cis` and `cispi` instead of `exp(im*x)` and `exp(im*pi*x)`.
---
### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [November 18, 2024, 5:35am UTC](https://discourse.julialang.org/t/can-symbolics-handle-complex-numbers/122753/3 "2024-11-18T05:35:25Z")
Use complex variables:
```julia
@variables C_0::Complex
```
---
### Author:  [@ccmejia](https://discourse.julialang.org/u/ccmejia)
#### Post date: [November 18, 2024, 12:06pm UTC](https://discourse.julialang.org/t/can-symbolics-handle-complex-numbers/122753/4 "2024-11-18T12:06:54Z")
Hi!
By declaring
```julia
@variables C_0::Complex, C_1::Complex, R::Complex, T::Complex, V, k, R0, g
```
Now I obtain this error message:
> AssertionError: Expected a variable, got C\_0
> Stacktrace:
> [1] check\_x(x::Complex{Num})
Any ideas?
Thanks in advanced!
---
### Author:  [@ChrisRackauckas](https://discourse.julialang.org/u/ChrisRackauckas)
#### Post date: [November 18, 2024, 12:41pm UTC](https://discourse.julialang.org/t/can-symbolics-handle-complex-numbers/122753/5 "2024-11-18T12:41:40Z")
Open an issue.