Quadratic Function Graphing Practice - Parameter a, b, c

Master plotting quadratic functions y=ax²+bx+c with step-by-step practice problems. Learn vertex formulas, x-intercepts, and parameter effects on parabola shape.

📚Practice Plotting Quadratic Functions with Parameters
  • Determine parabola direction using coefficient a (upward/downward facing)
  • Calculate vertex coordinates using the formula x = -b/(2a)
  • Find x-intercepts by solving ax² + bx + c = 0
  • Analyze how parameters a, b, c affect parabola shape and position
  • Graph complete quadratic functions on coordinate systems step-by-step
  • Identify y-intercept and vertical shifts using constant term c

Understanding Plotting Functions with Parameters

Complete explanation with examples

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.
Detailed explanation

Practice Plotting Functions with Parameters

Test your knowledge with 18 quizzes

Create an algebraic expression based on the following parameters:

\( a=2,b=\frac{1}{2},c=4 \)

Examples with solutions for Plotting Functions with Parameters

Step-by-step solutions included
Exercise #1

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

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

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

Video Solution
Exercise #2

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

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

Video Solution
Exercise #3

Identify the coefficients based on the following equation

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

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

Video Solution
Exercise #4

Identify the coefficients based on the following equation

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

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

Video Solution
Exercise #5

Identify the coefficients based on the following equation

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

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

Video Solution

Frequently Asked Questions

How do you determine if a quadratic function opens upward or downward?

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Look at the coefficient 'a' in y = ax² + bx + c. If a > 0, the parabola opens upward (smiling). If a < 0, the parabola opens downward (sad or crying).

What is the vertex formula for quadratic functions?

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The x-coordinate of the vertex is x = -b/(2a). Substitute this value back into the function to find the y-coordinate. The vertex is the highest or lowest point of the parabola.

How do parameters a, b, and c affect the quadratic graph?

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Parameter 'a' determines direction and width: larger |a| makes narrower parabolas. Parameter 'b' affects position and slope at y-intercept. Parameter 'c' is the y-intercept and causes vertical shifts.

What are the steps to graph a quadratic function?

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1) Check if a is positive or negative for direction 2) Find vertex using x = -b/(2a) 3) Find x-intercepts by setting y = 0 4) Plot vertex, intercepts, and draw the parabola

How do you find x-intercepts of quadratic functions?

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Set y = 0 and solve the equation ax² + bx + c = 0. Use factoring, quadratic formula, or completing the square. These points show where the parabola crosses the x-axis.

What does the constant term c represent in y = ax² + bx + c?

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The constant term 'c' is the y-intercept - where the parabola crosses the y-axis. It also represents the vertical shift of the basic parabola y = ax².

Why must coefficient a be non-zero in quadratic functions?

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If a = 0, the function becomes y = bx + c, which is linear, not quadratic. The x² term with coefficient 'a' is what makes the function quadratic and creates the parabolic shape.

How does the size of coefficient a affect parabola width?

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Larger absolute values of 'a' create narrower parabolas, while smaller absolute values create wider parabolas. For example, |a| = 4 is narrower than |a| = 0.5.

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