I have an expression that looks like
a (3 x^2 + \[Lambda] - 2 x (1 + \[Lambda])) +
x (x^2 + 3 \[Lambda] - 2 x (1 + \[Lambda]))
and I want to find the values of 'a' and \[Lambda] that makes it a perfect cubic (i.e., can be factored as (x-b)^3)
I think you need to use FindInstance for this, but can't quite work out how... any help please?