Find the first integral term in the expansion of (√3+3√2)9
Let the first integral term be Tr+1
Tr+1=9Cr(312)9−r(213)r
= (39−r2)(2r3)
We get the first integral term when r=3(Both r3 and 9−r2 should be integers. One way of proceeding is start with 0, then 1,2,3. When r=3, we get the first integral term)
⇒T4=9C43321
=549C4