Quadratic Function Practice Problems & Solutions

Master quadratic functions with step-by-step practice problems. Learn to find vertices, intercepts, and graph parabolas with confidence.

📚Practice Your Quadratic Function Skills
  • Find the vertex of parabolas using the vertex formula
  • Determine if a parabola opens upward or downward
  • Calculate x and y intercepts of quadratic functions
  • Identify increasing and decreasing intervals from graphs
  • Solve quadratic equations using factoring and quadratic formula
  • Graph minimum and maximum parabolas accurately

Understanding Function

Complete explanation with examples

Function

What is a function?

A function is an equation that describes a specific relationship between XX and YY.
Every time we change XX, we get a different YY.

Linear function –

Looks like a straight line, XX is in the first degree.

Quadratic function –

Parabola, XX is in the square.

Detailed explanation

Practice Function

Test your knowledge with 20 quizzes

Given the linear function:

\( y=1-4x \)

What is the rate of change of the function?

Examples with solutions for Function

Step-by-step solutions included
Exercise #1

For the function in front of you, the slope is?

XY

Step-by-Step Solution

For this problem, we need to determine the nature of the slope for a given straight line on a graph.

Based on the graph provided, the red line starts at a higher point on the left (Y-axis) and moves downward toward a lower point on the right (X-axis). This indicates that as one moves from left to right across the graph, the function decreases in value. Consequently, this is typical of a line that has a negative slope.

The slope of a line is typically defined as the "rise over the run," or the ratio of the change in the vertical direction to the change in the horizontal direction. Here, as we proceed from left to right, the line goes "downwards" (negative rise), establishing a negative slope.

Thus, we can conclude that the slope of the line is negative.

Therefore, the solution to the problem is Negative slope.

Answer:

Negative slope

Video Solution
Exercise #2

For the function in front of you, the slope is?

XY

Step-by-Step Solution

To determine the slope of the line segment shown in the graph, follow these steps:

  • Identify the line segment on the graph; it's shown as a red line from one point to another.
  • Examine the direction the line segment travels from the leftmost point to the rightmost point.
  • Visually analyze whether the line segment is rising or falling as it moves from left to right.

Here is the detailed analysis:
- The red line segment starts lower on the left side and ends higher on the right side.
- This suggests that as we move from left to right, the line is rising.
- In terms of slope, a line that rises as it moves from left to right has a positive slope.

Therefore, the slope of the line segment is positive.

Thus, the correct answer is Positive slope.

Answer:

Positive slope

Video Solution
Exercise #3

For the function in front of you, the slope is?

XY

Step-by-Step Solution

To determine the slope of the line shown on the graph, we perform a visual analysis:

  • We examine the orientation of the line from left to right.
  • The red line starts at a higher point on the left and descends to a lower point on the right.
  • This indicates a downward movement, which corresponds to a negative slope.

Therefore, by observing the direction of the line, we conclude that the slope of the function is negative. This positional evaluation confirms that the correct answer is negative slope.

Answer:

Negative slope

Video Solution
Exercise #4

For the function in front of you, the slope is?

XY

Step-by-Step Solution

To determine the slope of the line, we'll examine the direction of the line segment on the graph:

  • The line depicted moves from the top left, passing through a point with higher y y -coordinate values, to the bottom right, ending at a point with lower y y -coordinate values.
  • This movement indicates that as x x increases (the direction to the right along the x x -axis), the y y -coordinate decreases.
  • When the y y -value reduces as the x x -value grows, the slope m m is negative.

Since the line descends from left to right, the slope of the line is negative.

Therefore, the slope of the function is a negative slope.

Answer:

Negative slope

Video Solution
Exercise #5

For the function in front of you, the slope is?

XY

Step-by-Step Solution

To solve this problem, follow these steps:

  • Step 1: Observe the given graph and the plotted line.
  • Step 2: Determine the direction of the line as it moves from left to right across the graph.
  • Step 3: Understand that a line moving downwards from left to right represents a negative slope.

Now, let's work through these steps:

Step 1: The graph shows a straight line that starts higher on the left side and descends towards the right side.

Step 2: As the line moves from left to right, it descends. This is a key indicator of the slope type.

Step 3: A line that moves downward from the left side to the right side of the graph (decreasing in height as it proceeds to the right) is characteristic of a negative slope. Conversely, a positive slope would show a line ascending as it moves rightward.

Therefore, the solution to the problem is the line has a negative slope.

Answer:

Negative slope

Video Solution

Frequently Asked Questions

How do I find the vertex of a quadratic function?

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Use the vertex formula X = -b/(2a) to find the x-coordinate, then substitute this value back into the original equation to find the y-coordinate. You can also use two symmetrical points and find their midpoint.

What's the difference between minimum and maximum parabolas?

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A minimum parabola (smiling) opens upward when a > 0, with the vertex as the lowest point. A maximum parabola (sad) opens downward when a < 0, with the vertex as the highest point.

How do I find where a parabola crosses the x-axis?

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Set y = 0 in the quadratic equation and solve for x using factoring, completing the square, or the quadratic formula. The solutions are your x-intercepts.

What does the coefficient 'a' tell me about a quadratic function?

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The coefficient 'a' determines the parabola's direction and width. If a > 0, it opens upward (minimum). If a < 0, it opens downward (maximum). Larger |a| values make narrower parabolas.

How do I determine increasing and decreasing intervals?

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For minimum parabolas: decreasing for x < vertex x-value, increasing for x > vertex x-value. For maximum parabolas: increasing for x < vertex x-value, decreasing for x > vertex x-value.

What's the standard form of a quadratic function?

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The standard form is y = ax² + bx + c, where 'a' cannot equal zero. This form makes it easy to identify the y-intercept (c) and calculate the vertex using formulas.

How do I find the y-intercept of a quadratic function?

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Substitute x = 0 into the equation. The y-intercept is simply the constant term 'c' in the standard form y = ax² + bx + c.

Why is understanding parabolas important in real life?

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Parabolas model many real-world situations like projectile motion, satellite dishes, bridge arches, and profit optimization in business. Understanding their properties helps solve practical problems.

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