Binomial Theorem And Its Simple Applications Question 212

Question: $ \sqrt{5}[{{(\sqrt{5}+1)}^{50}}-{{(\sqrt{5}-1)}^{50}}] $ is

Options:

A) An irrational number

B) 0

C) A natural number

D) None of these

Show Answer

Answer:

Correct Answer: C

Solution:

  • [c] $ \sqrt{5}[ {{( \sqrt{5}+1 )}^{50}}-{{( \sqrt{5}-1 )}^{50}} ] $

$ =2\sqrt{5}[ ^{50}C_1{{( \sqrt{5} )}^{49}}+{{,}^{50}}C_3{{( \sqrt{5} )}^{47}}+…. ] $

$ =2[ ^{50}C_1{{( \sqrt{5} )}^{50}}+{{,}^{50}}C_3{{( \sqrt{5} )}^{48}}+…. ] $ = a natural number