Processing math: 100%

User interface language: English | Español

Date November 2017 Marks available 3 Reference code 17N.1.hl.TZ0.3
Level HL only Paper 1 Time zone TZ0
Command term Find Question number 3 Adapted from N/A

Question

Consider the polynomial q(x)=3x311x2+kx+8.

Given that q(x) has a factor (x4), find the value of k.

[3]
a.

Hence or otherwise, factorize q(x) as a product of linear factors.

[3]
b.

Markscheme

q(4)=0     (M1)

192176+4k+8=0 (24+4k=0)     A1

k=6     A1

[3 marks]

a.

3x311x26x+8=(x4)(3x2+px2)

equate coefficients of x2:     (M1)

12+p=11

p=1

(x4)(3x2+x2)     (A1)

(x4)(3x2)(x+1)     A1

 

Note:     Allow part (b) marks if any of this work is seen in part (a).

 

Note:     Allow equivalent methods (eg, synthetic division) for the M marks in each part.

 

[3 marks]

b.

Examiners report

[N/A]
a.
[N/A]
b.

Syllabus sections

Topic 2 - Core: Functions and equations » 2.5 » Polynomial functions and their graphs.

View options