How you calculate this? #abs((a,a+1,a+2),(a+1,a+3,a+1),(a+2,a+1,a))#
Here we need to evaluate a Determinant.
Have a look:
Row reduction doesn't affect the determinant so here:
Now take the determinant from the bottom row as it's got a zero:
This matrix is symmetric but that doesn't help when it comes to determinants.
We will simplify