User interface language: English | Español

Date May 2018 Marks available 2 Reference code 18M.2.AHL.TZ1.H_5
Level Additional Higher Level Paper Paper 2 Time zone Time zone 1
Command term Find Question number H_5 Adapted from N/A

Question

Given that  2 x 3 3 x + 1 can be expressed in the form  A x ( x 2 + 1 ) + B x + C , find the values of the constants  A B and  C .

[2]
a.

Hence find 2 x 3 3 x + 1 x 2 + 1 d x .

[5]
b.

Markscheme

* This question is from an exam for a previous syllabus, and may contain minor differences in marking or structure.

2 x 3 3 x + 1 = A x ( x 2 + 1 ) + B x + C

A = 2 , C = 1 ,      A1

A + B = 3 B = 5      A1

[2 marks]

a.

2 x 3 3 x + 1 x 2 + 1 d x = ( 2 x 5 x x 2 + 1 + 1 x 2 + 1 ) d x       M1M1

Note: Award M1 for dividing by  ( x 2 + 1 ) to get  2 x , M1 for separating the  5 x and 1.

= x 2 5 2 ln ( x 2 + 1 ) + arctan x ( + c )      (M1)A1A1

Note: Award (M1)A1 for integrating  5 x x 2 + 1 , A1 for the other two terms.

[5 marks]

b.

Examiners report

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

Syllabus sections

Topic 5 —Calculus » SL 5.10—Indefinite integration, reverse chain, by substitution
Show 54 related questions
Topic 5 —Calculus

View options