The Zeros of a Quadratic Polynomial

Oct 13, 2025 by wbrum.org 76 views

Introduction

In algebra, a quadratic polynomial is a polynomial of degree two, which means the highest power of the variable is two. The general form of a quadratic polynomial is ${ax^2 + bx + c}$ , where ${a}$ , ${b}$ , and ${c}$ are constants. The zeros of a quadratic polynomial are the values of ${x}$ that make the polynomial equal to zero. In this article, we will discuss how to find the quadratic polynomial whose zeros are given.

The Zeros of a Quadratic Polynomial

The zeros of a quadratic polynomial can be found using the quadratic formula: ${x = \frac{-b \pm \sqrt{b^2 - 4ac}}{2a}}$ . However, in this case, the zeros are given as ${5-2 \sqrt{3}}$ and ${5+2 \sqrt{3}}$ . We can use this information to find the quadratic polynomial.

The Sum and Product of the Zeros

The sum of the zeros of a quadratic polynomial is equal to ${-\frac{b}{a}}$ , and the product of the zeros is equal to ${\frac{c}{a}}$ . We can use this information to find the values of ${a}$ , ${b}$ , and ${c}$ .

Let's start by finding the sum of the zeros:

${(5-2 \sqrt{3}) + (5+2 \sqrt{3}) = 10}$

Since the sum of the zeros is equal to ${-\frac{b}{a}}$ , we can write:

${-\frac{b}{a} = 10}$

Now, let's find the product of the zeros:

${(5-2 \sqrt{3})(5+2 \sqrt{3}) = 25 - 12 = 13}$

Since the product of the zeros is equal to ${\frac{c}{a}}$ , we can write:

${\frac{c}{a} = 13}$

Finding the Quadratic Polynomial

Now that we have the sum and product of the zeros, we can find the quadratic polynomial. We know that the sum of the zeros is equal to ${-\frac{b}{a}}$ , and the product of the zeros is equal to ${\frac{c}{a}}$ . We can use this information to write the quadratic polynomial in the form ${ax^2 + bx + c}$ .

Since the sum of the zeros is equal to ${-\frac{b}{a}}$ , we can write:

${a(x + \frac{b}{a}) = 10}$

Simplifying, we get:

${x + \frac{b}{a} = 10}$

Multiplying both sides by ${a}$ , we get:

${ax + b = 10a}$

Now, let's substitute the value of ${b}$ in terms of ${a}$ and ${c}$ :

${b = -10a}$

Substituting this value of ${b}$ into the equation, we get:

${ax - 10a = 10a}$

Simplifying, we get:

${ax = 20a}$

Dividing both sides by ${a}$ , we get:

${x = 20}$

However, this is not the correct solution. We need to find the quadratic polynomial in the form ${ax^2 + bx + c}$ .

Let's try a different approach. We know that the product of the zeros is equal to ${\frac{c}{a}}$ . We can write:

${c = 13a}$

Now, let's substitute the value of ${c}$ in terms of ${a}$ into the equation:

${ax^2 + bx + 13a = 0}$

We know that the sum of the zeros is equal to ${-\frac{b}{a}}$ . We can write:

${-\frac{b}{a} = 10}$

Multiplying both sides by ${a}$ , we get:

${-b = 10a}$

Dividing both sides by ${-1}$ , we get:

${b = -10a}$

Substituting this value of ${b}$ into the equation, we get:

${ax^2 - 10ax + 13a = 0}$

Dividing both sides by ${a}$ , we get:

${x^2 - 10x + 13 = 0}$

Conclusion

In this article, we discussed how to find the quadratic polynomial whose zeros are given. We used the sum and product of the zeros to find the values of ${a}$ , ${b}$ , and ${c}$ . We then used this information to write the quadratic polynomial in the form ${ax^2 + bx + c}$ . The final answer is:

${x^2 - 10x + 13}$

This is option D in the given choices.

Final Answer

The final answer is option D: ${x^2 - 10x + 13}$ .

Introduction

In the previous article, we discussed how to find the quadratic polynomial whose zeros are given. In this article, we will answer some frequently asked questions related to quadratic polynomial zeros.

Q: What are the zeros of a quadratic polynomial?

A: The zeros of a quadratic polynomial are the values of ${x}$ that make the polynomial equal to zero.

Q: How do I find the sum and product of the zeros of a quadratic polynomial?

A: To find the sum and product of the zeros of a quadratic polynomial, you can use the following formulas:

Sum of the zeros: ${-\frac{b}{a}}$
Product of the zeros: ${\frac{c}{a}}$

Q: What is the relationship between the sum and product of the zeros and the coefficients of a quadratic polynomial?

A: The sum and product of the zeros are related to the coefficients of a quadratic polynomial as follows:

Sum of the zeros: ${-\frac{b}{a}}$
Product of the zeros: ${\frac{c}{a}}$

Q: How do I find the quadratic polynomial whose zeros are given?

A: To find the quadratic polynomial whose zeros are given, you can use the following steps:

Find the sum and product of the zeros.
Use the sum and product of the zeros to find the values of ${a}$ , ${b}$ , and ${c}$ .
Write the quadratic polynomial in the form ${ax^2 + bx + c}$ .

Q: What is the difference between the sum and product of the zeros and the coefficients of a quadratic polynomial?

A: The sum and product of the zeros are related to the coefficients of a quadratic polynomial, but they are not the same thing. The sum and product of the zeros are used to find the values of ${a}$ , ${b}$ , and ${c}$ , which are then used to write the quadratic polynomial in the form ${ax^2 + bx + c}$ .

Q: Can I find the quadratic polynomial whose zeros are given using other methods?

A: Yes, you can find the quadratic polynomial whose zeros are given using other methods, such as factoring or using the quadratic formula. However, the method we discussed in the previous article is a simple and straightforward way to find the quadratic polynomial.

Q: What are some common mistakes to avoid when finding the quadratic polynomial whose zeros are given?

A: Some common mistakes to avoid when finding the quadratic polynomial whose zeros are given include:

Not using the correct formulas for the sum and product of the zeros.
Not using the correct values of ${a}$ , ${b}$ , and ${c}$ .
Not writing the quadratic polynomial in the correct form.

Q: How do I check my answer to make sure it is correct?

A: To check your answer, you can plug the zeros back into the quadratic polynomial and make sure that it equals zero. You can also use the quadratic formula to check your answer.

Q: What are some real-world applications of quadratic polynomial zeros?

A: Quadratic polynomial zeros have many real-world applications, including:

Physics: Quadratic polynomial zeros are used to model the motion of objects under the influence of gravity.
Engineering: Quadratic polynomial zeros are used to design and optimize systems, such as bridges and buildings.
Economics: Quadratic polynomial zeros are used to model economic systems and make predictions about future trends.

Conclusion

In this article, we answered some frequently asked questions related to quadratic polynomial zeros. We discussed the relationship between the sum and product of the zeros and the coefficients of a quadratic polynomial, and we provided some tips and tricks for finding the quadratic polynomial whose zeros are given. We also discussed some common mistakes to avoid and some real-world applications of quadratic polynomial zeros.