Plotting the Quadratic Function

Plotting the graph of the quadratic function and examining the roles of the parameters a,b,ca, b, c in the function of the form y=ax2+bx+cy = ax^2 + bx + c

The quadratic function has three relevant characteristics:

aa – the coefficient of X2X^2.
bb – the coefficient of XX.
cc – the constant term.

Steps to graph a quadratic function –

  1. Let's examine the parameter aa and ask: Is the function upward or downward facing?
  2. Let's find the vertex of the function using the formula and then find the Y-coordinate of the vertex.
  3. Let's find the points of intersection with the XX axis by substituting (Y=0Y=0).
  4. Let's draw a coordinate system and first mark the vertex of the parabola.
    Then, let's examine if the function is smiling or crying and mark the points of intersection with the XX axis that we found. Draw accordingly.

Suggested Topics to Practice in Advance

  1. The quadratic function
  2. Parabola

Practice Plotting Functions with Parameters

Examples with solutions for Plotting Functions with Parameters

Exercise #1

Determine the value of the coefficient a a in the following equation:

x2+7x9 -x^2+7x-9

Video Solution

Step-by-Step Solution

The quadratic equation in the problem is already arranged (meaning all terms are on one side and 0 on the other side), so let's proceed to answer the question asked:

The question asked in the problem - What is the value of the coefficienta a in the equation?

Let's recall the definitions of coefficients in solving quadratic equations and the roots formula:

The rule states that the roots of an equation of the form:

ax2+bx+c=0 ax^2+bx+c=0 are:

x1,2=b±b24ac2a x_{1,2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}

That is the coefficient a a is the coefficient of the quadratic term (meaning the term with the second power)- x2 x^2 Let's examine the equation in the problem:

x2+7x9=0 -x^2+7x-9 =0

Remember that the minus sign before the quadratic term means multiplication by: 1 -1 , therefore- we can write the equation as:

1x2+7x9=0 -1\cdot x^2+7x-9 =0

The number that multiplies the x2 x^2 , is 1 -1 hence we identify that the coefficient of the quadratic term is the number 1 -1 ,

Therefore the correct answer is A.

Answer

-1

Exercise #2

What is the value of the coefficient b b in the equation below?

3x2+8x5 3x^2+8x-5

Video Solution

Step-by-Step Solution

The quadratic equation of the given problem is already arranged (that is, all the terms are found on one side and the 0 on the other side), thus we approach the given problem as follows;

In the problem, the question was asked: what is the value of the coefficientb b in the equation?

Let's remember the definitions of coefficients when solving a quadratic equation as well as the formula for the roots:

The rule says that the roots of an equation of the form

ax2+bx+c=0 ax^2+bx+c=0 are :

x1,2=b±b24ac2a x_{1,2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}

That is the coefficientb b is the coefficient of the term in the first power -x x We then examine the equation of the given problem:

3x2+8x5=0 3x^2+8x-5 =0 That is, the number that multiplies

x x is

8 8 Consequently we are able to identify b, which is the coefficient of the term in the first power, as the number8 8 ,

Thus the correct answer is option d.

Answer

8

Exercise #3

What is the value of the coefficient c c in the equation below?

4x2+9x2 4x^2+9x-2

Video Solution

Step-by-Step Solution

The quadratic equation is given as 4x2+9x2 4x^2 + 9x - 2 . This equation is in the standard form of a quadratic equation, which is ax2+bx+c ax^2 + bx + c , where a a , b b , and c c are coefficients.

  • The term 4x2 4x^2 indicates that the coefficient a=4 a = 4 .
  • The term 9x 9x indicates that the coefficient b=9 b = 9 .
  • The constant term 2-2 indicates that the coefficient c=2 c = -2 .

From this analysis, we can see that the coefficient c c is 2-2.

Therefore, the value of the coefficient c c in the equation is 2-2.

Answer

-2

Exercise #4

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 #5

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 #6

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 #7

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 #8

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 #9

y=2x2+3x+10 y=-2x^2+3x+10

Video Solution

Step-by-Step Solution

Let's determine the coefficients for the quadratic function given by y=2x2+3x+10 y = -2x^2 + 3x + 10 .

  • Step 1: Identify a a .
    The coefficient of x2 x^2 is 2-2. Thus, a=2 a = -2 .
  • Step 2: Identify b b .
    The coefficient of x x is 33. Thus, b=3 b = 3 .
  • Step 3: Identify c c .
    The constant term is 1010. Thus, c=10 c = 10 .

Comparing these coefficients to the provided choices, the correct answer is:

a=2,b=3,c=10 a = -2, b = 3, c = 10 .

Therefore, the correct choice is Choice 4.

Answer

a=2,b=3,c=10 a=-2,b=3,c=10

Exercise #10

y=3x2+4x+5 y=3x^2+4x+5

Video Solution

Step-by-Step Solution

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

  • Step 1: Identify the given quadratic function.
  • Step 2: Compare it to the standard form y=ax2+bx+c y = ax^2 + bx + c .
  • Step 3: Determine the values of a a , b b , and c c .

Now, let's work through each step:

Step 1: The problem gives us the quadratic function y=3x2+4x+5 y = 3x^2 + 4x + 5 .

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

Step 3: By comparing y=3x2+4x+5 y = 3x^2 + 4x + 5 with y=ax2+bx+c y = ax^2 + bx + c , we find:
- The coefficient of x2 x^2 is a=3 a = 3 .
- The coefficient of x x is b=4 b = 4 .
- The constant term is c=5 c = 5 .

Therefore, the solution to the problem is a=3,b=4,c=5 a = 3, b = 4, c = 5 .

This matches choice 2, which states: a=3,b=4,c=5 a = 3, b = 4, c = 5 .

Answer

a=3,b=4,c=5 a=3,b=4,c=5

Exercise #11

What is the value of the coefficient c c in the equation below?

3x2+5x 3x^2+5x

Video Solution

Step-by-Step Solution

The quadratic equation of the given problem has already been arranged (that is, all the terms are on one side and 0 is on the other side) thus we can approach the question as follows:

In the problem, the question was asked: what is the value of the coefficientc c in the equation?

Let's remember the definition of a coefficient when solving a quadratic equation as well as the formula for the roots:

The rule says that the roots of an equation of the form

ax2+bx+c=0 ax^2+bx+c=0 are:

x1,2=b±b24ac2a x_{1,2}=\frac{-b\pm\sqrt{b^2-4ac}}{2a}

That is the coefficient
c c is the free term - and as such the coefficient of the term is raised to the power of zero -x0 x^0 (Any number other than zero raised to the power of zero equals 1:

x0=1 x^0=1 )

Next we examine the equation of the given problem:

3x2+5x=0 3x^2+5x=0 Note that there is no free term in the equation, that is, the numerical value of the free term is 0, in fact the equation can be written as follows:

3x2+5x+0=0 3x^2+5x+0=0 and therefore the value of the coefficientc c is 0.

Hence the correct answer is option c.

Answer

0

Exercise #12

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 #13

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 #14

y=4+3x2x y=4+3x^2-x

Video Solution

Step-by-Step Solution

To solve this problem, we will match the given quadratic equation with its standard form:

  • Step 1: Identify the standard quadratic form as y=ax2+bx+cy = ax^2 + bx + c.
  • Step 2: Compare with given equation y=4+3x2xy = 4 + 3x^2 - x.
  • Step 3: Determine the coefficients by arranging the equation in standard form.

Let's now perform the steps:

Step 1: The standard quadratic form is y=ax2+bx+cy = ax^2 + bx + c.

Step 2: The given equation is y=4+3x2xy = 4 + 3x^2 - x.

Step 3: Rearrange the given equation to match the standard form:

y=3x2x+4y = 3x^2 - x + 4.

Now, directly compare:

a=3a = 3

b=1b = -1

c=4c = 4

Therefore, the coefficients are correctly identified as a=3,b=1, a=3, b=-1, and c=4 c=4 .

The correct answer is: a=3,b=1,c=4 a=3, b=-1, c=4 .

Answer

a=3,b=1,c=4 a=3,b=-1,c=4

Exercise #15

y=3x2+45x y=3x^2+4-5x

Video Solution

Step-by-Step Solution

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

  • Step 1: Rearrange the given quadratic function into the standard form.
  • Step 2: Identify the coefficients by comparing them with the standard quadratic function.

Now let's work through each step:

Step 1: The given quadratic is y=3x2+45x y = 3x^2 + 4 - 5x . Rearrange this function to align terms with their degrees:
y=3x25x+4 y = 3x^2 - 5x + 4 .

Step 2: Compare this with the standard quadratic form y=ax2+bx+c y = ax^2 + bx + c , where:
a=3 a = 3 (the coefficient of x2x^2),
b=5 b = -5 (the coefficient of xx),
c=4 c = 4 (the constant term).

Therefore, the correct choice is a=3,b=5,c=4 a = 3, b = -5, c = 4 .

Answer

a=3,b=5,c=4 a=3,b=-5,c=4