SOLUTION: if X^4+aX^3-3X^2+2aX+a^2 is aperfect square and has a factor (X+2). find (a), when (a) has this vàlue to obtain the square root of the expression in its factorized form
This must be an identity
If x=0
If x=1
Substituting
Discriminant =
So it has imaginary solutions. We ignore
Substituting
Discriminant =
That has real solutions
So
Edwin