User interface language: English | Español

Date May Example question Marks available 1 Reference code EXM.1.AHL.TZ0.9
Level Additional Higher Level Paper Paper 1 Time zone Time zone 0
Command term Write down Question number 9 Adapted from N/A

Question

The matrix A (120311221)120311221  has inverse A−1 = (122311a6b)122311a6b.

Consider the simultaneous equations

x+2y=7x+2y=7

3x+yz=103x+yz=10

2x2y+z=122x2y+z=12

Write down the value of aa.

[1]
a.i.

Write down the value of bb.

[1]
a.ii.

Write these equations as a matrix equation.

[1]
b.

Solve the matrix equation.

[3]
c.

Markscheme

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

aa = 4       A1 N1

[1 mark]

a.i.

bb = 7       A1 N1

[1 mark]

a.ii.

EITHER

A(xyz)=(71012)xyz=71012      A1 N1

OR

(120311221)(xyz)=(71012)120311221xyz=71012      A1 N1

[1 mark]

b.

(xyz)xyzA−1 (71012)71012     (accept algebraic method)         (M1)

(xyz)=(354)xyz=354     (accept xx = −3, yy = 5, zz = 4)        A2    N3

[3 marks]

c.

Examiners report

[N/A]
a.i.
[N/A]
a.ii.
[N/A]
b.
[N/A]
c.

Syllabus sections

Topic 1—Number and algebra » AHL 1.14—Introduction to matrices
Show 139 related questions
Topic 1—Number and algebra

View options