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Date November 2008 Marks available 6 Reference code 08N.1.hl.TZ0.1
Level HL only Paper 1 Time zone TZ0
Command term Find Question number 1 Adapted from N/A

Question

When \(f(x) = {x^4} + 3{x^3} + p{x^2} - 2x + q\) is divided by (x − 2) the remainder is 15, and (x + 3) is a factor of f(x) .

Find the values of p and q .

Markscheme

\(f(2) = 16 + 24 + 4p - 4 + q = 15\)     M1

\( \Rightarrow 4p + q = - 21\)     A1

\(f( - 3) = 81 - 81 + 9p + 6 + q = 0\)     M1

\( \Rightarrow 9p + q = - 6\)     A1

\( \Rightarrow p = 3{\text{ and }}q = - 33\)     A1A1     N0

[6 marks]

Examiners report

Most candidates made a meaningful attempt at this question. Weaker candidates often made arithmetic errors and a few candidates tried using long division, which also often resulted in arithmetic errors. Overall there were many fully correct solutions.

Syllabus sections

Topic 2 - Core: Functions and equations » 2.5 » The factor and remainder theorems.

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