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Can someone please explain the answers?

Can someone please explain the answers?-example-1
User Bonatti
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1 Answer

3 votes

Answer:

3. Fifth degree polynomials are also known as quintic polynomials. Quintics have these characteristics: One to five roots. Zero to four extrema.

4. x = -5 or x = 0 or x = 5

Explanation:

Solve for x:

6 x^5 - 150 x^3 = 0

The left hand side factors into a product with four terms:

6 x^3 (x - 5) (x + 5) = 0

Divide both sides by 6:

x^3 (x - 5) (x + 5) = 0

Split into three equations:

x - 5 = 0 or x^3 = 0 or x + 5 = 0

Add 5 to both sides:

x = 5 or x^3 = 0 or x + 5 = 0

Taking cube roots gives 0 times the third roots of unity:

x = 5 or x = 0 or x = 0 or x = 0 or x + 5 = 0

Subtract 5 from both sides:

x = 5 or x = 0 or x = 0 or x = 0 or x = -5

There are {2} duplicate solutions:

Answer: x = -5 or x = 0 or x = 5

User Arocks
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