... bx3+6cx 2 − 4 dx+ ewith a>0, we define the invariantsA = ae − 4bd +3c 2 ,B= ace +2bcd − ad 2 − eb 2 − c3,∆1= A3− 27 B 2 ,∆ 2 = b 2 − ac,∆3= c 2 − bd, ∆4= d 2 − ce,W1= ad − bc, W 2 = ... and {2, 2} means two double real roots.condition real roots∆1> 0 ∧T>0 ∧ ∆ 2 > 0 {1, 1, 1, 1}∆1> 0 ∧(T ≤ 0 ∨ ∆ 2 ≤ 0) {}∆1< 0 {1, 1}∆1=0∧ T>0 {2, 1, 1}∆1=0∧ T<0 ... 1}∆1=0∧ T>0 {2, 1, 1}∆1=0∧ T<0 {2} ∆1=0∧ T =0∧∆ 2 > 0 ∧R =0 {2, 2} ∆1=0∧ T =0∧∆ 2 > 0 ∧R =0{3, 1}∆1=0∧ T =0∧∆ 2 < 0 {}∆1=0∧ T =0∧∆ 2 =0 {4}The next theorem provides a...