Quadratic form Factor the polynomial X4 3X2 2?

If you mean x^4 + 3x^2 +2, then you would use any letter.

Say y = x^2

therefore x^4 + 3x^2 +2 must = y^2 + 3y + 2

you can now factorise this:

(y+2)(y+1)

so y = -2 or y = -1

Remember, y = x^2

so, -2 = x^2. square root this. But if you remember what you've been taught, then you cannot square root a (-). So, there are no solutions. This means that the line on the graph will not intersect the x-axis.

I hope this is what you are looking for.