Binomial Theorem And Its Simple Applications Question 160

Question: If $ {{(1+x-2x^{2})}^{6}}=1+a_1x+a_2x^{2}+….+a_{12}x^{12} $ , then the expression $ a_2+a_4+a_6+….+a_{12} $ has the value

[RPET 1986, 99; UPSEAT 2003]

Options:

A) 32

B) 63

C) 64

D) None of these

Show Answer

Answer:

Correct Answer: D

Solution:

  • $ {{(1+x-2x^{2})}^{6}}=1+a_1x+a_2x^{2}+….+a_{12}x^{12} $ .

Putting $ x=1 $ and x = - 1 and adding the results 64 = 2(1+a2+a4+…)

$ \therefore ,a_2+a_4+a_6+….+a_{12}=31 $ .