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Use synthetic substitution to find g(3) and g(–5) for the function g(x) = x5 – 8x3 – 2x + 7.

2 Answers

7 votes

Let's do the same thing to evaluate g(-5):

-5Answer:

Explanation:

Never heard of "synthetic substitution." I think you meant "synthetic division," which is a great method of evaluating polynomials for given input values.

g(x) = x^5 – 8x^3 – 2x + 7 is missing two terms.

With all terms showing, it would read:

g(x) = x^5 – 0x^4 + 8x^3 – 0x^2 - 2x + 7. The coefficients are {1, 0, 8, 0, -2, 7}.

Let's evaluate g(3). Use 3 as divisor in synth. div.:

3 ) 1 0 8 0 -2 7

3 9 51 153 453

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1 3 17 51 151 460 Since the remainder is 460, the value of g(3) is also 460.

-5 ) 1 9 8 0 -2 7

-5 -20 60 -300 1510

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1 4 -12 60 -302 1517

The remainder is 1517, and so g(-5) = 1517.

User Joe Lyga
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3 votes

Answer:

28, -2,108

Explanation:

User Aerus
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4.9k points