If Δ1=xbbaxbaax and Δ2=xbax are the given determinants, then
Δ1=3Δ22
ddxΔ1=3Δ2
ddxΔ1=3Δ22
Δ1=3Δ23/2
Δ1=xx2−ab−b(ax−ab)+ba2−ax =x3−3abx+ab2+a2b
ddxΔ1=3x2−3ab=3x2−ab=3Δ2