Josh graphs a system of equations to determine the roots of the polynomial equation [tex]x^5 = -2x^2[/tex]. From the graph, he determines that there are two solutions to the equation.

Which statement is true?

A. He is correct because the least exponent of the system is two so there must be two solutions.

B. He is correct because the graph shows two intersection points.

C. He is not correct because the difference of the exponents is three, so there must be three solutions, one of which is a multiplicity.

D. He is not correct because the greatest exponent of the system is five, so there must be five solutions, three of which must be multiplicities or complex.



Answer :

To determine the correct statement regarding the roots of the polynomial equation \( x^5 = -2x^2 \), let's analyze the equation step by step.

1. Rewrite the Equation: Start by rewriting the equation in standard polynomial form:
[tex]\[ x^5 + 2x^2 = 0 \][/tex]

2. Factor Out the Common Term: Factor out the common term \( x^2 \):
[tex]\[ x^2 (x^3 + 2) = 0 \][/tex]

3. Set Each Factor Equal to Zero: This gives us two separate equations to solve:
[tex]\[ x^2 = 0 \quad \text{and} \quad x^3 + 2 = 0 \][/tex]

4. Solve the First Equation: The first equation \( x^2 = 0 \) has a straightforward solution:
[tex]\[ x = 0 \][/tex]
This solution has a multiplicity of 2, meaning it counts as two solutions.

5. Solve the Second Equation: The second equation \( x^3 + 2 = 0 \) can be solved by isolating \( x \):
[tex]\[ x^3 = -2 \][/tex]
[tex]\[ x = \sqrt[3]{-2} \][/tex]
The cube root of -2 provides three complex roots (one real and two complex). The real root is:
[tex]\[ x = -\sqrt[3]{2} \][/tex]
The remaining two roots are complex.

6. Count All Solutions: Since the polynomial is of degree 5 (the highest exponent is 5), there must be 5 solutions in total. We have:
- Two solutions from \( x = 0 \) (with multiplicity 2)
- Three solutions from \( x^3 = -2 \) (one real and two complex)

Therefore, the polynomial equation \( x^5 = -2x^2 \) indeed has five solutions, considering both real and complex roots.

Conclusion:
The correct statement is:
He is not correct because the greatest exponent of the system is five, so there must be five solutions, three of which must be multiplicities or complex.

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