Length of LR =a2b2=10⇒5a=b2...(1)
f(t)=t2+t+1211dtdf(t)=2t+1=0⇒t=2−1 Min value of f(t)=(2−1)2+(2−1)+1211=412−1+1211=123−6+11=128=32=ee2=a21−b2⇒94=a21−b2
⇒a2b2=a1−4=a5⇒b2=a5a2...(2)
From (1) & (2) 5a=a5a2⇒a=9, b=45=35∴a2+b2=81+45=126