# Quadratic Function Q&A: Working w/ Numbers Below 10

• hell18
In summary, the conversation is about using a quadratic function to find the value of a variable, using the formula y = ax2 + bx + c. The person is practicing with numbers below 10 and is unsure if their calculation is correct. They clarify that the correct method is to first find the value of N2, then multiply it by 3 and add 4. The conversation ends with some confusion about the use of Y and N, but the summary remains the same.
hell18
2 questions

1.can a quadratic function be just set to 1 number e.g. 5 or can it be a bigger number. at the moment I am working on numbers below 10 to get used to the formulas.

2. is this correct how i am doing it?

formula

N --> N2--> 3N2 + 4

e.g.

N =5

5 x 5 = 25 = N2

5 x 25 = 75 = 3N2

N = 79 answer

is that correct?

Your questions are awkwardly written but I think what you want is:

given y= ax2+ bx+ c, you can choose x to be any number you want, then calculate y.

In particular, if y= 3N2+ 4, you would, just as you say, first, find N2, then multiply by 3, then add 4.

thats it, yea I am still practicing the equations. i thought Y2 were that if you had Y = 5 then Y2. Then to find Y2 we multiply the 5 by in this case Y2 to get 25 as Y2 would be 25 then mutliply 3N2 by the 25 to get 75 + 4 to get 79

is that ok?

I'm assuming that English is not your native language so I won't be quite as harsh as I could be!

that's it, yea I am still practicing the equations. i thought Y2 were that if you had Y = 5 then Y2. Then to find Y2 we multiply the 5 by in this case Y2 to get 25 as Y2 would be 25 then mutliply 3N2 by the 25 to get 75 + 4 to get 79

Much of this makes no since at all: "i thought Y2 were that if you had Y = 5 then Y2." Then what?? I assume you meant to write "then Y2= 52".

But you also write "Then to find Y2 we multiply the 5 by in this case Y2". No, you multiply 5 by itself- that's what "2" means.

"then mutliply 3N2 by the 25". No, "N2" is 25. You only multiply the 3 by 25. By the way, it's a really, really bad idea to suddenly switch from "Y" to "N".

To calculate 3N2+ 4, for N= 5, you replace the N by 5:
3(5)2+ 4= 3(25)+ 4= 75+ 4= 79.

## 1. What is a quadratic function?

A quadratic function is a polynomial equation of the form y = ax^2 + bx + c, where a, b, and c are constants and x is the variable. It is a type of function that follows a parabolic shape when graphed.

## 2. How do you solve a quadratic equation?

There are several methods for solving a quadratic equation, such as factoring, completing the square, and using the quadratic formula. The most commonly used method is the quadratic formula, which is x = (-b ± √(b^2 - 4ac)) / 2a. Plug in the values of a, b, and c into the formula and solve for x.

## 3. What is the discriminant of a quadratic function?

The discriminant is a value that is used to determine the nature of the solutions to a quadratic equation. It is calculated by taking the square root of the expression b^2 - 4ac. If the discriminant is positive, the equation will have two real solutions. If it is zero, there will be one real solution. And if it is negative, there will be no real solutions, only complex solutions.

## 4. How do you graph a quadratic function?

To graph a quadratic function, you can use a table of values or plot points by finding the x and y-intercepts. Another method is to use the vertex form of the function, y = a(x-h)^2 + k, where (h,k) is the vertex of the parabola. You can also use transformations, such as shifting, reflecting, and stretching, to graph a quadratic function.

## 5. What are some real-life applications of quadratic functions?

Quadratic functions are used in many real-life scenarios, such as calculating the trajectory of a projectile, modeling the growth of a population, and predicting the profit of a business. They are also used in engineering, physics, and other sciences to describe motion, energy, and other phenomena.

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