4x^4+1+4x^2=(2x^2+1)^2
4x^4+1+4x^2=(2x^2+1)^24x^4+1-4x^2=(2x^2-1)^24x^4+1+4x^8=(2x^4+1)^24x^4+1-1=(2x^2)^2
4x^4+1-4x^2 =(2x^2-1)^2=(1-2x^2)^2
