# Not evaluating the coordinates

I have the following code

```
D(f,m)=16*f^4*m^4 + (-144*f^10 + 432*f^9 - 472*f^8 - 1040*f^7 + 1672*f^6 + 784*f^5 - 3256*f^4 - 2896*f^3 - 392*f^2 + 128*f - 64)*m^2 + (36*f^14 - 468*f^13 + 3321*f^12 + 1224*f^11 - 8982*f^10 + 10332*f^9 + 29583*f^8 + 144*f^7 - 21024*f^6 - 4572*f^5 + 7047*f^4 + 3816*f^3 + 306*f^2 - 108*f + 81)
[(f,m) for m in [-10..10] for f in [-10..10] if D==0]
```

where I want to find all values of `(f,m)`

that gives `D=0`

. I have checked using Pari that one of the point is `(-1,0)`

, and also, `(1,2)`

. But when i run the coding it gives empty set.