Problem

Write the sum using sigma notation.
\[
1-2 x+3 x^{2}-4 x^{3}+5 x^{4}+\ldots-94 x^{93}
\]

Answer

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Answer

This is the sigma notation for the given series.

Steps

Step 1 :First, we observe the pattern in the given series. We see that the coefficient of each term is one more than the power of \(x\) in the previous term.

Step 2 :The power of \(x\) in each term is one less than the coefficient of the term.

Step 3 :The sign of each term alternates, starting with positive.

Step 4 :We can express this pattern using sigma notation as follows:

Step 5 :\(\sum_{n=0}^{93} (-1)^n (n+1) x^n\)

Step 6 :This is the sigma notation for the given series.

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