Find the multiplicative inverse of Z = -2i

Explanation

`LHS = C_(0) * ""^(2n)C_(n) - C_(1) * ""^(2n-1)C_(n) + C_(2) . ""^(2n-4)C_(n) - ...` ltbrge Coefficient of ` x^(n)` in
` [C_(0)(1 + x)^(2n) - C_(1) (1 + x)^(2n-2) + C_(2) (1 + x)^(2n-4)-...]`
= Coefficient of ` x^(n) ` in
`[C_(0) (1 + x)^(2)]^(n) C_(1) [ (1 + x)^(n) ]^(n-1) = C_(2) [(1 + x)^(2)] ^(n-2) - ...]`
= Coefficient of ` x^(n) " in" (1 x)^(n) [((1 +x)-1)^(n)]`
= Coefficient of ` x^(n) "in" (1 + x)^(n) * x^(n) d `
= Constant term in ` (1 +x)^(n) = 1 = RHS `