216. Quadratic Parameters

Learning Intentions

  • Identify parameters in quadratic functions.
  • Describe how parameter changes affect the shape and position of a parabola.
  • Compare algebraic changes with graphical transformations.

Pre-requisite Summary

  • Understand quadratic functions in the form .
  • Recognise the role of coefficients in shaping graphs.
  • Plot basic parabolas using tables of values.
  • Identify intercepts and turning points.
  • Understand graph transformations (shifts and stretches).
  • Substitute values into quadratic expressions.

Worked Examples

Worked Example 1

Identify the parameters in:

State the values of:

Worked Example 2

Compare:

and

Worked Example 3

Compare:

and

Worked Example 4

Compare:

and

Worked Example 5

Compare algebraic and graphical change:

Problems

Problem 1

Identify , , and in:

Problem 2

Describe the effect of:

Problem 3

Describe the transformation:

Problem 4

Describe the transformation:

Problem 5

Explain the effect of:

Exercises

Understanding and Fluency

Exercise 1

Identify parameters , , :

Exercise 2

Identify parameters:

Exercise 3

Identify parameters:

Exercise 4

Describe effect of changing :

Exercise 5

Describe effect of changing :

Exercise 6

Describe effect of:

Exercise 7

Describe shift:

Exercise 8

Describe shift:

Exercise 9

State what changes when changes in

Exercise 10

State what remains unchanged when only changes

Exercise 11

Explain why affects the “width” of a parabola.

Exercise 12

Explain why only affects vertical position.

Exercise 13

A student says:

“Changing only moves the graph up or down.”

Explain the error.

Exercise 14

Explain the difference between:

Exercise 15

Interpret:

Exercise 16

Compare:

A:

B:

Exercise 17

Describe the full transformation:

Potential Misunderstandings

  • Thinking only shifts the graph (it affects vertex position).
  • Confusing with the turning point.
  • Assuming all changes affect shape (only affects shape).
  • Misunderstanding as shifting left instead of right.
  • Forgetting negative reflects the graph.
  • Mixing expansion form with vertex form.
  • Assuming symmetry changes when changes.

Next: 217. Exploring Linear and Quadratic Relations with Digital Tools