A) 2
B) 4
C) 6
D) 7
Correct Answer: A
Solution :
[A] \[{{(1+{{x}^{2}})}^{2}}\,\,{{(1+x)}^{n}}\]\[=(1+2{{x}^{2}}+{{x}^{4}})\,\,{{(}^{n}}{{C}_{0}}{{+}^{n}}{{C}_{1}}\,x{{+}^{n}}{{C}_{2}}\,{{x}^{2}}+....)\]\[=\,{{\,}^{n}}{{C}_{0}}+{{\,}^{n}}{{C}_{1}}x+({{\,}^{n}}{{C}_{2}}+2.{{\,}^{n}}{{C}_{0}})\,\,{{x}^{2}}+......)\] Hence \[{{A}_{0}}=1;\,\,{{A}_{1}}{{=}^{n}}{{C}_{1}};\]\[{{A}_{2}}=\,{{\,}^{n}}{{C}_{2}}+2\] which are in A.P.You need to login to perform this action.
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