Day 4 STAAR Review - Characteristics of Quadratic Functions

Which graph best represents a quadratic function that has two zeros?**

What tool can we use to solve this?

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Answer explanation

Tool: Vocabulary

Zeros are the same as x-intercepts.

• {5,12}

• {-12,-5}

• {-3,20}

• {-20,3}

Answer explanation

Tool: Calculator graph & vocabulary.

Another word for solution is x-intercepts.

• All real numbers greater than or equal to 0 and less than or equal to 4

• All real numbers greater than or equal to 0 and less than or equal to 121

• All real numbers greater than or equal to 1.25 and less than or equal to 4

• All real numbers greater than or equal to 96 and less than or equal to 121

Answer explanation

Tool: Vocabulary.

The domain of the graph is the set of x-values from left to right with respect to the x-axis.

Answer explanation

Tools include: Calculator graph & vocabulary Another word for zeros are x-intercepts. To write factored form, you must change the signs of the x-intercepts.

The table shows the speed of a vehicle in miles per hour, x, and the fuel economy of the vehicle in miles per gallon, f(x).

Which quadratic function best models the data in the table?**

What tool can we use to solve this?

Answer explanation

Tool: List & Spreadsheet - Quadratic Regression

The quadratic function f(x) = x² is transformed to create the graph of g(x) = f(x – c) + d, where d is a positive number. Select three points that represent a possible vertex of the graph of g.

Select THREE correct answers.**

What tool(s) can we use to solve this?

Answer explanation

If there is +d, graph vertically shifts up.

Answer explanation

Tool: Calculator graph and calculator match answer choices.

Other possible tool: Quadratic Formula

The three points shown lie on the graph of a parabola that represents a quadratic function.

Which equation best represents the axis of symmetry of this function?**

What tool(s) can we use to solve this?

Answer explanation

Tool: Vocabulary

Axis of symmetry is a line that can split the graph in half or be in the middle of the two points in this graph.

The range of a quadratic function is the set of all real numbers less than or equal to 3. Which equations could represent the function?**

Select TWO correct answers.

What tool(s) can we use to solve this?

Answer explanation

Tool(s): Calculator graph & vocabulary.

Range is the set of the lowest y-values to the highest y-values with respect to the y-axis.

The graph of a quadratic function is shown.

Which value best represents the minimum of the function?**

What tool(s) can we use to solve this?

• -2

• -3

• -4

• -1

Answer explanation

Tool(s): Vocabulary

Minimum value is the lowest y-value of the vertex.