Question

15 Find the coefficient of x2 in the expansion of
(x2 + x + 1)2 + (x2-x + 1)2
Hint. Given expression = f(x2 + 1) + x)2 + {(x2 +1) - x)2
= 2((x2 + 1)² + x²).
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Answer 1

here is your answer