Precalculus : Find Complex Zeros of a Polynomial Using the Fundamental Theorem of Algebra

Study concepts, example questions & explanations for Precalculus

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Example Questions

Example Question #431 : Pre Calculus

Find a fourth-degree polynomial whose zeroes are , and 

Possible Answers:

Correct answer:

Explanation:

This one is a bit of a journey. The expressions for the first two zeroes are easily calculated,  and  respectively. The last expression must be broken up into two equations:  which are then set equal to zero to yield the expressions  and

Finally, we multiply together all of the parenthesized expressions, which multiplies out to 

Example Question #432 : Pre Calculus

The third-degree polynomial expression  has a real zero at . Find all of the complex zeroes.

Possible Answers:

Correct answer:

Explanation:

First, factor the expression by grouping:

To find the complex zeroes, set the term  equal to zero: 

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