A) 21
B) 25
C) 26
D) None of these
Correct Answer: D
Solution :
Since, \[{{(1+2x+3{{x}^{2}}+....)}^{-3/2}}={{[{{(1-x)}^{-2}}]}^{-3/2}}\] \[={{(1-x)}^{3}}\] So, coefficient of \[{{x}^{5}}\] in \[{{(1+2x+3{{x}^{2}}+...)}^{-3/2}}\] = Coefficient of \[{{x}^{n}}\] in \[{{(1-x)}^{3}}=0\]You need to login to perform this action.
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