Find the roots of each of the following equations, if they exist, by applying the quadratic formula:
12abx2−(9a2−8b2)x−6ab=0, where a≠0 and b≠0
Using quadratic formula
12abx2−(9a2−8b2)x−6ab=0A=12abB=−(9a2−8b2)C=−6ab
∴Discriminant, D=B2−4AC=(−(9a2−8b2))2−4×(12ab)×(−6ab)=81a4+144a2b2+64b4=(9a2+8b2)2≥0
As D≥0 therefore, the roots are real.
x=−B±√D2A=−(−(9a2−8b2))±√(9a2+8b2)22(12ab)=(9a2−8b2)±(9a2+8b2)24ab=(9a2−8b2)+(9a2+8b2)24ab or (9a2−8b2)−(9a2+8b2)24ab=9a2−8b2+9a2+8b224ab or 9a2−8b2−9a2−8b224ab=18a224ab or −16b224ab=3a4b or −2b3a