The sum of the co-efficients of all odd degree terms in the expansion of is :
- (A)2✓ Correct
- (B)-1
- (C)0
- (D)1
Answer: (A)
Solution
Only even powers of survive in . With this is . Collecting the odd-degree terms gives , and setting to add their coefficients gives .
JEE Main · 2018 · 08 Apr 2018 · Offline · Single correct option