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Precalculus Polynomial and Rational Functions Study Guide

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Q1. Classify the polynomial f(x) = -9 - x as constant, linear, quadratic, cubic, or quartic. Also, determine the leading term, the leading coefficient, and the degree of the polynomial.

Background

Topic: Polynomial Classification and Terminology

This question tests your understanding of how to classify polynomials by degree and identify key features such as the leading term, leading coefficient, and degree.

Key Terms:

  • Degree: The highest power of x in the polynomial.

  • Leading Term: The term with the highest degree.

  • Leading Coefficient: The coefficient of the leading term.

  • Polynomial Types: Constant (degree 0), Linear (degree 1), Quadratic (degree 2), Cubic (degree 3), Quartic (degree 4).

Step-by-Step Guidance

  1. Rewrite the polynomial in standard form (descending powers of x).

  2. Identify the term with the highest power of x; this is the leading term.

  3. Determine the degree by looking at the exponent of the leading term.

  4. Find the coefficient of the leading term; this is the leading coefficient.

  5. Classify the polynomial based on its degree.

Try solving on your own before revealing the answer!

Final Answer:

Linear; leading term: ; leading coefficient: ; degree: $1$.

The polynomial is linear because the highest power of is $1$.

Q2. Classify the polynomial g(x) = 259x^2 + 4203x^3 as constant, linear, quadratic, cubic, or quartic. Also, determine the leading term, the leading coefficient, and the degree of the polynomial.

Background

Topic: Polynomial Classification and Terminology

This question is similar to Q1 and tests your ability to identify the degree, leading term, and leading coefficient of a polynomial.

Key Terms:

  • Standard form: Write terms in descending order of degree.

  • Leading term, leading coefficient, degree (see above).

Step-by-Step Guidance

  1. Rewrite the polynomial in standard form (highest degree first).

  2. Identify the term with the highest exponent; this is the leading term.

  3. Note the coefficient of the leading term; this is the leading coefficient.

  4. Determine the degree by the highest exponent.

  5. Classify the polynomial by its degree.

Try solving on your own before revealing the answer!

Final Answer:

Cubic; leading term: ; leading coefficient: $4203.

The highest power is $3$, so the polynomial is cubic.

Q3. Find the correct end behavior diagram for the given polynomial function: .

Background

Topic: End Behavior of Polynomial Functions

This question tests your understanding of how the degree and leading coefficient of a polynomial affect its end behavior as and .

Key Concepts:

  • For polynomials, the end behavior is determined by the leading term.

  • If the degree is odd and the leading coefficient is negative, the ends go in opposite directions.

  • General rule: For with odd and , as , ; as , .

Step-by-Step Guidance

  1. Identify the leading term of the polynomial.

  2. Determine the degree (odd or even) and the sign of the leading coefficient.

  3. Recall the end behavior rules for odd-degree polynomials with negative leading coefficients.

  4. Sketch or describe the general shape based on these rules.

Try solving on your own before revealing the answer!

Final Answer:

As , ; as , .

This matches the end behavior of an odd-degree polynomial with a negative leading coefficient.

Q4. Use substitution to determine whether -2 is a zero of the polynomial .

Background

Topic: Zeros of Polynomials

This question tests your ability to check if a given value is a zero of a polynomial by direct substitution.

Key Concepts:

  • A zero of a polynomial is a value such that .

Step-by-Step Guidance

  1. Substitute into the polynomial .

  2. Calculate each term: , , , and .

  3. Add the results to find .

  4. Check if to determine if -2 is a zero.

Try solving on your own before revealing the answer!

Final Answer:

No, -2 is not a zero of because .

Q5. Find the zeros of the polynomial function and state the multiplicity of each.

Background

Topic: Zeros and Multiplicity

This question tests your ability to find zeros from factored form and determine their multiplicities.

Key Concepts:

  • Zeros are values of that make .

  • Multiplicity is the exponent on each factor; it tells how many times a zero is repeated.

Step-by-Step Guidance

  1. Set each factor equal to zero: and .

  2. Solve for in each equation to find the zeros.

  3. Identify the multiplicity for each zero based on the exponent of the factor.

  4. List the zeros and their multiplicities.

Try solving on your own before revealing the answer!

Final Answer:

Zeros: (multiplicity 2), $9$ (multiplicity 3).

Each zero comes from setting the corresponding factor to zero and noting the exponent.

Q6. A formula relating an athlete's vertical leap (in inches) to hang time (in seconds) is . A professional basketball player has a vertical leap of 37 inches. What is his hang time? Round your answer to the nearest tenth of a second.

Background

Topic: Solving Quadratic Equations

This question tests your ability to solve for a variable in a quadratic equation.

Key Formula:

Step-by-Step Guidance

  1. Substitute into the formula: .

  2. Solve for by dividing both sides by 48.

  3. Take the square root of both sides to solve for .

  4. Round your answer to the nearest tenth.

Try solving on your own before revealing the answer!

Final Answer:

Hang time seconds.

After solving and taking the square root, you get approximately seconds.

Q7. For the function , find the maximum number of real zeros, the maximum number of x-intercepts, and the maximum number of turning points the graph can have.

Background

Topic: Properties of Polynomial Functions

This question tests your understanding of how the degree of a polynomial relates to its zeros, x-intercepts, and turning points.

Key Concepts:

  • The degree of the polynomial determines the maximum number of real zeros and x-intercepts.

  • The maximum number of turning points is one less than the degree.

Step-by-Step Guidance

  1. Identify the degree of the polynomial by finding the highest exponent.

  2. Recall that the maximum number of real zeros and x-intercepts is equal to the degree.

  3. The maximum number of turning points is degree minus one.

  4. State these maximums based on the degree.

Try solving on your own before revealing the answer!

Final Answer:

Maximum number of real zeros: 4; maximum number of x-intercepts: 4; maximum number of turning points: 3.

These are determined directly from the degree of the polynomial, which is 4.

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