Processing math: 100%

User interface language: English | Español

Date May 2018 Marks available 6 Reference code 18M.2.hl.TZ1.2
Level HL only Paper 2 Time zone TZ1
Command term Find Question number 2 Adapted from N/A

Question

The equation x25x7=0 has roots α and β. The equation x2+px+q=0 has roots α+1 and β+1. Find the value of p and the value of q.

Markscheme

METHOD 1

α+β=5,αβ=7     (M1)(A1)

Note: Award M1A0 if only one equation obtained.

(α+1)+(β+1)=5+2=7     A1

(α+1)(β+1)=αβ+(α+β)+1     (M1)

=7+5+1=1

p=7,q=1       A1A1

 

METHOD 2

α=5+532=6.1;β=5532=1.1     (M1)(A1)

α+1=7+532=7.1;β+1=7532=0.1     A1

(x7.14)(x+0.14)=x27x1     (M1)

p=7,q=1       A1A1

Note: Exact answers only.

[6 marks]

 

Examiners report

[N/A]

Syllabus sections

Topic 2 - Core: Functions and equations » 2.6 » Sum and product of the roots of polynomial equations.

View options