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Find the remainder of (x^10 + 2x^9 + 3x^8 +...+ 9x^2 + 10x + 11) ÷ (x-1)

User Joaopfg
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1 Answer

4 votes

Answer:

66

Explanation:

You want the remainder from (x^10 +2x^9 +3x^8 +...+10x +11)/(x -1).

Remainder

The remainder from dividing polynomial f(x) by (x-a) is the value f(a). Here, that means we can find the remainder by evaluating (x^10 +2x^9 +3x^8 +...+10x +11) for x=1. When we do that, we see the value is simply the sum of the coefficients:

f(1) = (1 + 2 + 3 + ... + 10 + 11) = (11)(11 +1)/2 = 66

The remainder from dividing by (x-1) is 66.

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Additional comment

The sum of integers 1..n is (n)(n+1)/2.

User Jaydeep Patel
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