f(x)=ax2+bx+c f\left(x\right)=ax^2+bx+c

Where a0 a\ne0 , since if the coefficient a a does not appear then it would not be a quadratic function.

The graph of a quadratic function will always be a parabola.

Example 1:

f(x)=8x22x+4 f\left(x\right)=8x^2-2x+4

It is a quadratic or second-degree function because its largest exponent is 2 2 .

Example 2:

f(x)=7x3+6x2+2x1 f\left(x\right)=-7x^3+6x^2+2x-1

This is not a second-degree function because, although it has an exponent 2 2 , its largest exponent is 3 3 .

Quadratic function

The equation of the basic quadratic function is: y=ax2+bx+cy=ax^2+bx+c

This way of writing them is called the general form of a second-degree function, where:

ax2 ax^2 is called the squared term, quadratic term, or second-degree term.

a a is the coefficient of the quadratic term.

bx bx is called the linear term or first-degree term.

b b is the coefficient of the linear term.

c c is the constant term.

x x is called the unknown of the function and represents the number or numbers that make the function or in this case the equation true.

Example:

f(x)=3x25x+2 f\left(x\right)=3x^2-5x+2

a=3 a=3 , b=5 b=-5 and c=2 c=2

We must remember that for an equation to be of second degree, a a must always be different from zero.


Practice The Quadratic Function

Examples with solutions for The Quadratic Function

Exercise #1

y=x2+x+5 y=x^2+x+5

Video Solution

Step-by-Step Solution

To solve this problem, we will identify the parameters of the given quadratic function step-by-step:

  • Step 1: Define the problem statement: We have y=x2+x+5 y = x^2 + x + 5 .
  • Step 2: Identify the standard form of a quadratic function, which is y=ax2+bx+c y = ax^2 + bx + c .
  • Step 3: Compare the given quadratic expression with the standard form to identify the coefficients.

Now, let's analyze the quadratic function provided:

From the given expression y=x2+x+5 y = x^2 + x + 5 :
- The coefficient of x2 x^2 is 1 1 , so a=1 a = 1 .
- The coefficient of x x is 1 1 , so b=1 b = 1 .
- The constant term is 5 5 , so c=5 c = 5 .

Therefore, the parameters of the quadratic function are a=1 a = 1 , b=1 b = 1 , and c=5 c = 5 .

Consequently, the correct choice from the provided options is (a=1,b=1,c=5) (a = 1, b = 1, c = 5) .

Answer

a=1,b=1,c=5 a=1,b=1,c=5

Exercise #2

y=x2+x+5 y=-x^2+x+5

Video Solution

Step-by-Step Solution

To solve the problem of identifying the coefficients in the quadratic function y=x2+x+5 y = -x^2 + x + 5 , we follow these steps:

  • Step 1: Write down the general form of a quadratic equation: y=ax2+bx+c y = ax^2 + bx + c .

  • Step 2: Compare the given equation y=x2+x+5 y = -x^2 + x + 5 to the general form.

  • Step 3: Identify the value of each coefficient:

    • The coefficient of x2 x^2 is 1-1, so a=1 a = -1 .

    • The coefficient of x x is +1+1, so b=1 b = 1 .

    • The constant term is +5+5, so c=5 c = 5 .

Therefore, the parameters of the quadratic function are a=1 a = -1 , b=1 b = 1 , and c=5 c = 5 .

This matches choice 2, confirming the parameters in the quadratic function.

Final Answer: a=1,b=1,c=5 a=-1, b=1, c=5 .

Answer

a=1,b=1,c=5 a=-1,b=1,c=5

Exercise #3

y=3x2+3x4 y=3x^2+3x-4

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Step 1: Compare the given quadratic function with the standard form.
  • Step 2: Directly identify the coefficients a a , b b , and c c .
  • Step 3: Verify the correct choice from the provided options, if applicable.

Now, let's work through each step:
Step 1: The given quadratic function is y=3x2+3x4 y = 3x^2 + 3x - 4 . The standard form for a quadratic equation is y=ax2+bx+c y = ax^2 + bx + c .
Step 2: By comparing the given equation to the standard form, we can identify the coefficients:
- a=3 a = 3 , from the term 3x2 3x^2 .
- b=3 b = 3 , from the term 3x 3x .
- c=4 c = -4 , from the constant term 4-4.
Step 3: With these values, compare them to the given choices. The choice that matches these values is option 3: a=3,b=3,c=4 a = 3, b = 3, c = -4 .

Therefore, the solution to the problem is a=3,b=3,c=4 a = 3, b = 3, c = -4 .

Answer

a=3,b=3,c=4 a=3,b=3,c=-4

Exercise #4

y=4x2+3 y=-4x^2+3

Video Solution

Step-by-Step Solution

To solve this problem, we'll compare the given quadratic function with its standard form:

  • Step 1: Recognize the given function as y=4x2+3 y = -4x^2 + 3 .
  • Step 2: Write down the standard form of a quadratic function, which is y=ax2+bx+c y = ax^2 + bx + c .
  • Step 3: Match corresponding terms to identify a a , b b , and c c .

Now, let's work through these steps:

Step 1: The given function is y=4x2+3 y = -4x^2 + 3 .

Step 2: The standard form of a quadratic function is y=ax2+bx+c y = ax^2 + bx + c .

Step 3: By direct comparison:
- The coefficient of x2 x^2 in the given expression is 4-4. Therefore, a=4 a = -4 .
- There is no x x term in the given expression, which implies the coefficient b=0 b = 0 .
- The constant term in the given expression is 3 3 , indicating c=3 c = 3 .

Therefore, the solution is a=4 a = -4, b=0 b = 0, c=3 c = 3, which matches with choice 3.

Answer

a=4,b=0,c=3 a=-4,b=0,c=3

Exercise #5

y=3x24 y=-3x^2-4

Video Solution

Step-by-Step Solution

To solve this problem, we will follow these steps:

  • Step 1: Identify the form of a standard quadratic equation.
  • Step 2: Compare the given function with the quadratic standard form.
  • Step 3: Match the coefficients to the given answer choices.

Now, let's work through each step:
Step 1: The standard form of a quadratic function is y=ax2+bx+c y = ax^2 + bx + c .
Step 2: Given the function y=3x24 y = -3x^2 - 4 , we compare this with the standard form:

  • Coefficient a a is associated with x2 x^2 . Here, a=3 a = -3 .
  • Coefficient b b is associated with x x . Since there is no x x term, b=0 b = 0 .
  • The constant term c c is the standalone number, which is c=4 c = -4 .
Step 3: Given the coefficients a=3 a = -3 , b=0 b = 0 , and c=4 c = -4 , match these with the choices provided. The correct choice is Choice 4: a=3,b=0,c=4 a = -3, b = 0, c = -4 .

Therefore, the solution to the problem is a=3,b=0,c=4 a = -3, b = 0, c = -4 .

Answer

a=3,b=0,c=4 a=-3,b=0,c=-4

Exercise #6

y=5x2 y=-5x^2

Video Solution

Step-by-Step Solution

To solve the problem, we'll identify the parameters a a , b b , and c c from the given quadratic function:

  • **Step 1**: Compare the given equation y=5x2 y = -5x^2 with the general quadratic form y=ax2+bx+c y = ax^2 + bx + c .
  • **Step 2**: Note that the coefficient of x2 x^2 is 5-5, hence a=5 a = -5 .
  • **Step 3**: Since there is no x x term, b=0 b = 0 .
  • **Step 4**: Since there is no constant term, c=0 c = 0 .

After identifying the parameters, we conclude:

The parameters for the quadratic function are a=5 a = -5 , b=0 b = 0 , c=0 c = 0 . Therefore, the correct choice is:

The correct answer is a=5,b=0,c=0 a = -5, b = 0, c = 0 .

Answer

a=5,b=0,c=0 a=-5,b=0,c=0

Exercise #7

y=x2+3x+40 y=-x^2+3x+40

Video Solution

Step-by-Step Solution

To solve this problem, we will follow these steps:

  • Step 1: Identify the given quadratic equation and its form.
  • Step 2: Directly match the coefficients of the given equation to the standard form y=ax2+bx+c y = ax^2 + bx + c .
  • Step 3: Compare with the provided choices and select the one that matches.

Now, let's work through each step:
Step 1: The given quadratic equation is y=x2+3x+40 y = -x^2 + 3x + 40 . This matches the form y=ax2+bx+c y = ax^2 + bx + c .

Step 2: By comparing the given equation to the standard form:
- The coefficient a a is the coefficient of x2 x^2 , which is 1-1.
- The coefficient b b is the coefficient of x x , which is 3 3 .
- The coefficient c c is the constant term, which is 40 40 .

Step 3: From the analysis, we identify a=1 a = -1 , b=3 b = 3 , c=40 c = 40 . We compare these with the provided choices.
The correct answer is: a=1,b=3,c=40 a=-1,b=3,c=40

Therefore, the solution to the problem matches choice 4.

Answer

a=1,b=3,c=40 a=-1,b=3,c=40

Exercise #8

y=3x281 y=3x^2-81

Video Solution

Step-by-Step Solution

To solve this problem, we will identify values of aa, bb, and cc in the quadratic function:

  • Step 1: Note the given equation y=3x281y = 3x^2 - 81.
  • Step 2: Compare it to the standard quadratic form y=ax2+bx+cy = ax^2 + bx + c.
  • Step 3: Match coefficients to find aa, bb, and cc.

Now, let's work through each step:
Step 1: The given equation is y=3x281y = 3x^2 - 81.
Step 2: Compare this to the standard form, y=ax2+bx+cy = ax^2 + bx + c. In this equation:
- The coefficient of x2x^2 is 3, hence a=3a = 3.
- There is no xx term, which means b=0b = 0.
- The constant term is 81-81, hence c=81c = -81.

Therefore, the solution to the problem is a=3,b=0,c=81 a = 3, b = 0, c = -81 .

Answer

a=3,b=0,c=81 a=3,b=0,c=-81

Exercise #9

y=x2 y=x^2

Video Solution

Step-by-Step Solution

To solve this problem, let's follow these steps:

  • Step 1: Recognize the standard form of a quadratic equation.
  • Step 2: Match the given function to the standard form.
  • Step 3: Identify each coefficient a a , b b , and c c .

Now, let's work through these steps:

Step 1: The standard form of a quadratic function is y=ax2+bx+c y = ax^2 + bx + c . Our goal is to identify a a , b b , and c c .

Step 2: We are given the function y=x2 y = x^2 . This can be aligned with the standard form as y=1x2+0x+0 y = 1 \cdot x^2 + 0 \cdot x + 0 .

Step 3: By comparing the given function y=x2 y = x^2 with the standard form, we can deduce:
- The coefficient of x2 x^2 is 1, so a=1 a = 1 .
- The linear term coefficient is missing, which implies b=0 b = 0 .
- There is no constant term, so c=0 c = 0 .

Therefore, the coefficients are a=1,b=0,c=0 a = 1, b = 0, c = 0 , corresponding to choice 1.

Answer

a=1,b=0,c=0 a=1,b=0,c=0

Exercise #10

y=2x2+3 y=2x^2+3

Video Solution

Step-by-Step Solution

To solve this problem, we will follow these steps:

  • Step 1: Identify each term in the given function y=2x2+3y = 2x^2 + 3.
  • Step 2: Compare the equation to the standard quadratic form y=ax2+bx+cy = ax^2 + bx + c.
  • Step 3: Determine the coefficients aa, bb, and cc.
  • Step 4: Match these coefficients to the correct multiple-choice option.

Step 1: The given function is y=2x2+3y = 2x^2 + 3. There is no xx term present.

Step 2: Compare this with the standard form y=ax2+bx+cy = ax^2 + bx + c:

  • The coefficient of x2x^2 is a=2a = 2.
  • The coefficient of xx is b=0b = 0 because there is no xx term.
  • The constant term is c=3c = 3.

Step 3: Therefore, the coefficients are a=2a = 2, b=0b = 0, and c=3c = 3.

Step 4: Review the multiple-choice options provided:

  • Choice 1: a=0a = 0, b=2b = 2, c=3c = 3
  • Choice 2: a=0a = 0, b=3b = 3, c=2c = 2
  • Choice 3: a=2a = 2, b=0b = 0, c=3c = 3
  • Choice 4: a=3a = 3, b=0b = 0, c=2c = 2

The correct choice is Choice 3: a=2a = 2, b=0b = 0, c=3c = 3.

Therefore, the solution to the problem is the values a=2a = 2, b=0b = 0, c=3c = 3 which correspond to choice 3.

Answer

a=2,b=0,c=3 a=2,b=0,c=3

Exercise #11

y=x2+10x y=x^2+10x

Video Solution

Step-by-Step Solution

Here we have a quadratic equation.

A quadratic equation is always constructed like this:

 

y=ax2+bx+c y = ax²+bx+c

 

Where a, b, and c are generally already known to us, and the X and Y points need to be discovered.

Firstly, it seems that in this formula we do not have the C,

Therefore, we understand it is equal to 0.

c=0 c = 0

 

a is the coefficient of X², here it does not have a coefficient, therefore

a=1 a = 1

 

b=10 b= 10

is the number that comes before the X that is not squared.

 

Answer

a=1,b=10,c=0 a=1,b=10,c=0

Exercise #12

y=x26x+4 y=x^2-6x+4

Video Solution

Step-by-Step Solution

To solve this problem, we'll clearly delineate the given expression and compare it to the standard quadratic form:

  • Step 1: Recognize the standard form of a quadratic equation as y=ax2+bx+c y = ax^2 + bx + c .
  • Step 2: Compare the given equation y=x26x+4 y = x^2 - 6x + 4 to the standard form.
  • Step 3: Identify coefficients:
    - The coefficient of x2 x^2 is a=1 a = 1 .
    - The coefficient of x x is b=6 b = -6 .
    - The constant term is c=4 c = 4 .

Therefore, the coefficients for the quadratic function y=x26x+4 y = x^2 - 6x + 4 are a=1 a = 1 , b=6 b = -6 , and c=4 c = 4 .

Among the provided choices, choice 3: a=1,b=6,c=4 a=1,b=-6,c=4 is the correct one.

Answer

a=1,b=6,c=4 a=1,b=-6,c=4

Exercise #13

y=2x25x+6 y=2x^2-5x+6

Video Solution

Step-by-Step Solution

In fact, a quadratic equation is composed as follows:

y = ax²-bx-c

 

That is,

a is the coefficient of x², in this case 2.
b is the coefficient of x, in this case 5.
And c is the number without a variable at the end, in this case 6.

Answer

a=2,b=5,c=6 a=2,b=-5,c=6

Exercise #14

y=2x23x6 y=2x^2-3x-6

Video Solution

Step-by-Step Solution

To solve this problem, we'll follow these steps:

  • Identify the given quadratic function.
  • Match it with the standard form of a quadratic equation y=ax2+bx+cy = ax^2 + bx + c.
  • Extract the values of aa, bb, and cc directly from the comparison.

Now, let's work through each step:
Step 1: The given quadratic function is y=2x23x6y = 2x^2 - 3x - 6.
Step 2: The standard form of a quadratic equation is y=ax2+bx+cy = ax^2 + bx + c.
Step 3: By matching the given quadratic function with the standard form:

- The coefficient of x2x^2 is 22, so a=2a = 2.
- The coefficient of xx is 3-3, so b=3b = -3.
- The constant term is 6-6, so c=6c = -6.

Therefore, the solution to the problem is a=2a = 2, b=3b = -3, c=6c = -6.

Answer

a=2,b=3,c=6 a=2,b=-3,c=-6

Exercise #15

y=5x24x30 y=5x^2-4x-30

Video Solution

Step-by-Step Solution

The given quadratic function is y=5x24x30 y = 5x^2 - 4x - 30 .
To identify the coefficients, let's compare this with the standard form of a quadratic equation, y=ax2+bx+c y = ax^2 + bx + c .

  • Step 1: Compare the terms of the given equation to the standard form.
  • Step 2: Identify each coefficient:
    For ax2 ax^2 , a=5 a = 5 in the term 5x2 5x^2 .
    For bx bx , b=4 b = -4 in the term 4x-4x.
    For the constant term c c , c=30 c = -30 .

Thus, we have identified the coefficients as a=5 a = 5 , b=4 b = -4 , and c=30 c = -30 .

Therefore, the correct answer is a=5,b=4,c=30 a = 5, b = -4, c = -30 .

The correct choice is .

Answer

a=5,b=4,c=30 a=5,b=-4,c=-30