By putting x= y-a/4=y -6/4= y-3/2 ;then substituting and expanding and adding I had
y^4-6y^3+54/4*y^2-108/8*y+6y^3-54/2*y^2+162/4*y -162/8 -5y^2 +15y -45/4 -10y +15
-3=0 , then by adding and combing like terms I have y^4 +(- 37/2*y^2) +32y^2 +(-231/16)=0 . then y^4 -37/2*y^2 +32y^2 -231/16=0 ;therefore e= -37/2 ,f =32 ,
g =-231/16 . Having previously derived,h^6 +2*e*h^4 +(e^2-4*g)*h^2 -f ^2=0 .
how do I get from this cubic to h^6 +(-13)*h^4 +46*h^2 -1=0 and deriving that h^2
equals 0.0218741248 ?