Processing math: 100%

User interface language: English | Español

Date May 2013 Marks available 4 Reference code 13M.1.hl.TZ2.3
Level HL only Paper 1 Time zone TZ2
Command term Expand Question number 3 Adapted from N/A

Question

Expand (23x)5 in ascending powers of x, simplifying coefficients.

Markscheme

clear attempt at binomial expansion for exponent 5     M1

25+5×24×(3x)+5×42×23×(3x)2+5×4×36×22×(3x)3

+5×4×3×224×2×(3x)4+(3x)5     (A1)

Note: Only award M1 if binomial coefficients are seen.

 

=32240x+720x21080x3+810x4243x5     A2

Note: Award A1 for correct moduli of coefficients and powers. A1 for correct signs.

 

Total [4 marks]

Examiners report

Generally well done. The majority of candidates obtained a quintic with correct alternating signs. A few candidates made arithmetic errors. A small number of candidates multiplied out the linear expression, often correctly.

Syllabus sections

Topic 1 - Core: Algebra » 1.3 » The binomial theorem: expansion of (a+b)n, nN .
Show 22 related questions

View options