Graphs 8

3 marks · Normal

The graph of is reflected in the y-axis and then stretched in the y-direction by a scale factor of 2. Write down the equation of the resulting graph, and describe each transformation algebraically.

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y = 2f(-x)

Also accept: y = 2f(-x)

Common mistakes: Writing y = f(-2x); Reversing order: y = f(-2x)

Show mark scheme and worked solution

Marking points

M1 · 1 mark · States or uses the reflection: .

M2 · 1 mark · Stretches the graph in the y-direction: .

A1 · 1 mark · Writes the final equation correctly as .

Worked solution

Reflection in y-axis:

Stretch by factor 2 in y: