IGCSE Further Maths – Matrices Exercise 1 – Matrix Multiplication (questions from AQA Worksheets) Question 1 Work out (a) 4 2 7 3 5 1 (b) 5 0 3 0 5 4 (c) 5 2 2 6 3 (d) 1 0 3 0 1 2 (e) 4 7 6 1 3 (f) 8 4 3 4 2 6 Question 2 2 1 A = 3 4 2 3 C = 1 1 7 4 B = 5 3 Work out (a) AB (b) BC (c) 3A (d) BA (e) C (f) 1 4 B 5 7 Question 3 2 0 P = 5 1 4 1 Q = 3 2 3 C = 2 Work out (a) P2 (b) QP (c) 5Q (d) PC (e) IQ (f) 3I Question 4 Work out (a) 2 1 0 3 1 3 1 4 (b) 3 2 2 4 1 5 3 4 (c) 3 2 5 2 7 5 7 3 (d) 10 7 2 4 8 2 3 9 (e) 1 2 2 3 3 5 1 4 (f) 2 3 1 2 1 4 3 5 Question 5 (Non-calculator) Work out, giving your answers as simply as possible. (a) 2 1 2 0 1 3 2 3 2 2 (b) 1 2 3 2 1 5 2 4 1 3 2 (c) 3 2 7 5 2 3 3 2 (d) 4 3 1 3 3 4 0 1 3 2 3 (e) 1 2 1 4 (f) 2 3 1 4 2 7 2 3 2 Question 6 Work out, giving your answers as simply as possible. p p 1 (a) 1 0 0 1 (d) 2 0 a 0 2 0 0 a (b) 3 0 x 0 3 y (c) 0 1 m 1 0 2m (e) 4t 0 3 0 0 4t 0 3 (f) 1 0 0 1 1 0 3 0 1 2 Question 7 Work out, giving your answers as simply as possible. (a) 2 x 3 x 3x 5 4x 3 0 (b) 8 a 3a 7 2 1 10 11 (c) x 0 1 x (d) y 3 (e) a a 1 a a 1 a 2 a 1 a 2 a 1 (f) 3x 3 9 x 1 y x 2 3y 0 1 Exercise 1b Question 1 Question 3 Question 2 2 −1 0 0 ) (𝑎 𝑏 a) Work out ( 1 ) 𝑐 3 Give your answer in terms of 𝒂, 𝒃, 𝒄. 2 −1 0 𝑏 b) If ( 1 0 ) ( ) = 𝑰 where 𝑰 is the identity 𝑎 𝑐 3 matrix, work out the values of 𝑎, 𝑏, 𝑐. Question 4 2 2 Exercise 2 1. [Jan 2013 Paper 2 Q15] Describe fully the single transformation represented by the 0 −1 matrix ( ) 1 0 2. [Set 2 Paper 1 Q4] The transformation matrix 𝑎 2 ( ) maps the point (3,4) onto the −1 1 point (2, 𝑏). Work out the values of 𝑎 and 𝑏. 𝑎 𝑏 3. [Set 3 Paper 1 Q6] The matrix ( ) −𝑎 2𝑏 maps the point (5,4) onto the point (1,17). Work out the values of 𝑎 and 𝑏. 4. [Worksheet 2 Q5] Work out the image of the point D (1, 2) after transformation by the 2 3 matrix ( ) −1 1 5. [Worksheet 2 Q6] The point A(m, n) is transformed to the point A (2, 0) by the 2 3 matrix ( ) 1 1 Work out the values of m and n. 6. [Worksheet 2 Q8] Describe fully the transformation given by the matrix 0 −1 ( ) −1 0 7. [Worksheet 2 Q9] The unit square OABC is ℎ 0 transformed by the matrix ( ) to the 0 ℎ square OABC. The area of OABC is 27. Work out the exact value of h. 8. [Specimen Paper 2 Q20] (a) Matrix 𝑨 = 4 3 ( ) 1 1 Work out the image of point 𝑃(2, −1) using transformation matrix 𝑨. (b) Point 𝑄 is (0,1) Line 𝑃𝑄 is transformed to line 𝑃′𝑄′ using matrix 𝑨. Work out the length of 𝑃′𝑄′. Exercise 3 1. Point (3, −2) is transformed by the matrix 1 −1 ( ) followed by a further 0 1 0 2 transformation by the matrix ( ). 1 0 (i) Work out the matrix for the combined transformation. (ii) Work out the co-ordinates of the image point of 𝑃. 2. Point (−1,4) is transformed by the matrix 3 −1 ( ) followed by a further −2 2 1 0 transformation by the matrix ( ). 3 −2 (i) Work out the matrix for the combined transformation. (ii) Work out the co-ordinates of the image point of 𝑊. 3. The unit square is reflected in the 𝑥-axis followed by a rotation through 180° centre the origin. Work out the matrix for the combined transformation. 4. The unit square is enlarged, centre the origin, scale factor 2 followed by a reflection in the line 𝑦 = 𝑥. Work out the matrix for the combined transformation. −1 0 5. [Jan 2013 Paper 2 Q17] ( ) represents 0 1 0 1 a reflection in the 𝑦-axis. ( ) represents 1 0 a reflection in the line 𝑦 = 𝑥. Work out the matrix that represents a reflection in the 𝑦-axis followed by a reflection in the line 𝑦 = 𝑥. 6. [June 2012 Paper Q22] The transformation 0 −1 matrix ( ) maps a point 𝑃 to 𝑄. The −1 0 1 0 transformation matrix ( ) maps point 0 −1 𝑄 to point 𝑅. Point 𝑅 is (−4,3). Work out the coordinates of point 𝑃. 7. [Set 1 Paper Q14b] The unit square OABC is transformed by reflection in the line 𝑦 = 𝑥 followed by enlargement about the origin with scale factor 2. What is the matrix of the combined transformation? 3 0 −1 0 8. 𝐴 = ( ) and 𝐵 = ( ). 0 3 0 1 The point 𝑃(2,7) is transformed by matrix 𝐵𝐴 to 𝑃′. Show that 𝑃′ lies on the line 7𝑥 + 2𝑦 = 0.