Question
Question: The coefficient of t<sup>32</sup> in the expansion of (1 + t<sup>2</sup>)<sup>12</sup> (1 + t<sup>12...
The coefficient of t32 in the expansion of (1 + t2)12 (1 + t12) (1 + t24) is –
A
12C6 + 2
B
12C5
C
12C6
D
12C7
Answer
12C6 + 2
Explanation
Solution
We have, (1 + t2)12 (1 + t12) (1 + t24)
= (1 + 12C1t2 + 12C2t4 + ..... + 12C4t8 + .. + 12C10t20 + ...) (1 + t12 + t24 + t36)
\ Coefficient of t32 in (1 + t2)12 (1 + t12) (1 + t24) = 12C6 + 2.