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What is the Product of Roots of a Quadratic Equation?

Grade Level:

Class 6

AI/ML, Data Science, Physics, Economics, Cryptography, Computer Science, Engineering

Definition
What is it?

The 'Product of Roots' of a quadratic equation is the result you get when you multiply its two solutions, also called 'roots'. For any quadratic equation in the standard form ax^2 + bx + c = 0, this product is always equal to c/a.

Simple Example
Quick Example

Imagine a quadratic equation whose solutions (roots) are 2 and 3. If you multiply these two roots together (2 * 3), you get 6. This 6 is the 'product of roots' for that specific equation.

Worked Example
Step-by-Step

Let's find the product of roots for the equation 2x^2 + 10x + 12 = 0.

1. First, identify the coefficients a, b, and c from the standard form ax^2 + bx + c = 0.
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2. In our equation, 2x^2 + 10x + 12 = 0, we have:
a = 2
b = 10
c = 12
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3. The formula for the product of roots is c/a.
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4. Substitute the values of c and a into the formula.
Product of Roots = c/a = 12/2
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5. Calculate the final value.
Product of Roots = 6

So, the product of roots for the equation 2x^2 + 10x + 12 = 0 is 6.

Why It Matters

Understanding the product of roots helps engineers design structures and computer scientists optimize algorithms without solving the full equation. It's crucial in fields like Physics for predicting projectile paths and in Data Science for building predictive models, opening doors to careers in AI and machine learning.

Common Mistakes

MISTAKE: Forgetting the sign of 'c' or 'a' when using the formula c/a. For example, using c= -12 as 12. | CORRECTION: Always include the sign (+ or -) of 'c' and 'a' when substituting into the formula.

MISTAKE: Confusing the product of roots formula (c/a) with the sum of roots formula (-b/a). | CORRECTION: Remember 'P' for Product goes with 'C' for c/a, and 'S' for Sum goes with 'B' for -b/a. Think of it like a memory trick: 'Product is C, Sum is B'.

MISTAKE: Not ensuring the equation is in standard form (ax^2 + bx + c = 0) before identifying a, b, and c. For example, if the equation is 2x^2 + 12 = -10x. | CORRECTION: Always rearrange the equation so all terms are on one side and it equals zero, then identify a, b, and c correctly.

Practice Questions
Try It Yourself

QUESTION: Find the product of roots for the equation x^2 + 7x + 10 = 0. | ANSWER: 10

QUESTION: What is the product of roots for the equation 3x^2 - 15x + 9 = 0? | ANSWER: 3

QUESTION: If the equation is 5x^2 - 20 = 0, what is the product of its roots? (Hint: What is 'b' here?) | ANSWER: -4

MCQ
Quick Quiz

For the quadratic equation 4x^2 - 8x + 16 = 0, what is the product of its roots?

2

4

-2

-4

The Correct Answer Is:

B

The formula for the product of roots is c/a. In the equation 4x^2 - 8x + 16 = 0, a=4 and c=16. So, c/a = 16/4 = 4.

Real World Connection
In the Real World

Imagine a drone delivering packages in a city. Engineers use quadratic equations to calculate the drone's flight path. Knowing the product of roots can help them quickly estimate landing points or adjust trajectory without complex calculations, making deliveries like those by Zomato or Swiggy more efficient and precise.

Key Vocabulary
Key Terms

QUADRATIC EQUATION: An equation where the highest power of the variable is 2, like ax^2 + bx + c = 0. | ROOTS: The solutions or values of 'x' that make a quadratic equation true. | COEFFICIENTS: The numbers multiplied by the variables in an equation (a, b, c). | STANDARD FORM: The way a quadratic equation is usually written: ax^2 + bx + c = 0.

What's Next
What to Learn Next

Now that you know about the product of roots, you can learn about the 'Sum of Roots' of a quadratic equation. This will give you another quick way to understand properties of quadratic equations without fully solving them.

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