Date | May 2019 | Marks available | 2 | Reference code | 19M.1.AHL.TZ0.F_3 |
Level | Additional Higher Level | Paper | Paper 1 | Time zone | Time zone 0 |
Command term | Deduce | Question number | F_3 | Adapted from | N/A |
Question
The matrix A is given by A .
The matrix B is given by B .
Show that the eigenvalues of A are real if .
Deduce that the eigenvalues are real if A is symmetric.
Determine the eigenvalues of B.
Determine the corresponding eigenvectors.
Markscheme
the eigenvalues satisfy
M1
A1
A1
the condition for real roots is
M1
AG
[4 marks]
if the matrix is symmetric, b = c. In this case, M1
because each square term is non-negative R1AG
[2 marks]
the characteristic equation is
M1
A1
[2 marks]
taking
M1
giving eigenvector A1
taking
M1
giving eigenvector A1
[4 marks]