IB skill practice

Use inverse matrices in applications

Use inverse-matrix logic to recover inputs from a linear model.

Paper 1, Paper 2 5 marks Difficulty 4

Use inverse matrices in applications - interpretation demand

A sports institute linear model uses \(A=\begin{pmatrix}2&1\\1&3nd{pmatrix}\). The output vector is \(\begin{pmatrix}10\\15nd{pmatrix}\). Use \(A^{-1}\) to recover the first input. Enter the requested value and choose the interpretation that matches the result.

Worked practice: result and interpretation

Calculate the requested result first, then choose the interpretation that follows from it.