O-LevelAdditional MathematicsEquations, inequalities and graphs4037/22 · May/June 2019 · Q66 Marks
State the order of the matrix `(0 1 4 8; 5 8 1 6)`.
- (a)State the order of the matrix `(0 1 4 8; 5 8 1 6)`.[1]
- (b)(i)Given `A = (2 -4; -1 3)`. Find A⁻¹.[2]
- (b)(ii)Hence, given that ABA = I, find the matrix B.[3]
Mark scheme
Marking points from the official mark scheme (May/June 2019). The mark or mark type is shown in brackets.
- [B1] (a) 2 x 4 or 2 by 4
- [B2] (b)(i) (1/2) * (3 4; 1 2) isw (B1 for (1/detA) * adjA or for k * (3 4; 1 2) where k is not 0 or 1)
- [B3] (b)(ii) (1/4) * (13 20; 5 8) oe isw (FT their A⁻¹ provided B1 earned in (b)(i). B1 for the strategy of using A⁻¹: B = A⁻¹ A⁻¹ soi or AB = A⁻¹ soi or BA = A⁻¹ soi or B = (A⁻¹)² and B1 for two or three elements of B correct or correct FT)
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →