" 13.If "(1+x+x^(2))^(n)=a_(0)+a_(1)x+a_(2)x^(2)+....+a_(2n)x^(2n)" then "a_(0)+a_(3)+a_(6)+a_(9)+....=

If (1+x+x^(2))^(n)=a_(0)+a_(1)x+a_(2)x^(2)+...+a_(2n)x^(2n), then a_(0)+a_(2)+a_(4)+....+a_(2n) is

If n ge 2 , and (1 + x + x^(2))^(n) = a_(0) + a_(1)x + a_(2)x^(2) + .. . +a_(2n) x^(2n) , then a_(0) - 2a_(1)+ 3a_(2) + ... + (2n + 1)a_(n) = ______

If (1 +x + x^(2))^(n) = a_(0) + a_(1) x + a_(2) x^(2) + … + a_(2n) x^(2n) , then a_(0) + a_(2) + a_(4) + … + a_(2n) equals

If (1+x+x^(2))^(n)=a_(0)+a_(1)x+a_(2)x^(2)+….+a_(2n)x^(2n) , then prove that a_(0)+a_(3)+a_(6)+a_(9)+……=3^(n-1)

If (1+x+x^(2))^(n)=a_(0)+a_(1)x+a_(2)x^(2)+….+a_(2n)x^(2n) , then prove that a_(0)+a_(3)+a_(6)+a_(9)+……=3^(n-1)

( 1 + x + x^(2))^(n) = a_(0) + a_(1) x + a_(2) x^(2) + …+ a_(2n) x^(2n) , then a_(0) + a_(1) + a_(2) + a_(3) - a_(4) + … a_(2n) = .

(1+x)^(n)=a_(0)+a_(1)x+a_(2)*x^(2)+......+a_(n)x^(n) then prove that

If (1+x+x^(2))^(n)=a_(0)+a_(1)x+a_(2)x^(2)+......a_(2)nx^(2n) Find the value of a_(0)+a_(3)+a_(6)+......;!=psi lon N