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Date May 2010 Marks available 6 Reference code 10M.1.hl.TZ2.2
Level HL only Paper 1 Time zone TZ2
Command term Describe Question number 2 Adapted from N/A

Question

(a)     Express the quadratic 3x26x+5 in the form a(x+b)2+c, where a, b, c Z.

(b)     Describe a sequence of transformations that transforms the graph of y=x2 to the graph of y=3x26x+5.

Markscheme

(a)     attempt at completing the square     (M1)

3x26x+5=3(x22x)+5=3(x1)21+5     (A1)

=3(x1)2+2     A1

(a=3, b=1, c=2)

 

(b)     definition of suitable basic transformations:

T1= stretch in y direction scale factor 3     A1

T2= translation (10)     A1

T3= translation (02)     A1

[6 marks]

Examiners report

There were fewer correct solutions to this question than might be expected with a significant minority of candidates unable to complete the square successfully and a number of candidates unable to describe the transformations. A minority of candidates knew the correct terminology for the transformations and this potentially highlights the need for teachers to teach students appropriate terminology.

Syllabus sections

Topic 2 - Core: Functions and equations » 2.3 » Transformations of graphs: translations; stretches; reflections in the axes.

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