Question
Mathematics Question on Differential equations
The coefficient of xn in the expansion of e7x+exe3x is
A
(A) 4n−1−(−2)n−1⌊n
B
(B) 4n−1−2n−1⌊n
C
(C) 4n−2n⌊n
D
(D) 4n+(−2)n⌊n
Answer
(D) 4n+(−2)n⌊n
Explanation
Solution
Explanation:
e7x+eπe3x=e4x+e−2xCo-efficient of xn(4)nn!+(2)nn!(−1)n=4n+(−2)nn!