Q.

The coefficient of x2 in the expansion of (2x2+1x)10, x≠0, is:          [2026]

1 3240  
2 3360  
3 3480  
4 3600  

Ans.

(2)

We have, (2x2+1x)10, x≠0

Tr+1=Cr10(2x2)10–r(1x)r

⇒ Tr+1=Cr10(2)10–r·(x)20–3r

We have to find coefficient of x2

∴  20–3r=2 ⇒ 3r=18 ⇒ r=6

∴  Coefficient of x2=C610(2)10–6

⇒ C610(2)4=210×16=3360