Sum of coefficients in expansion of {(1 + x + {x^2})^n} is

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7.Binomial Theorem

easy

The sum of coefficients in the expansion of ${(1 + x + {x^2})^n}$ is

A

$2$

B

${3^n}$

C

${4^n}$

D

${2^n}$

Solution

(b) We can obtain sum of coefficients by putting $x = 1$ in polynomial.

==> ${(1 + x + {x^2})^n} = {(1 + 1 + 1)^n} = {3^n}$.

Standard 11

Mathematics

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