IB skill practice

Compose linear functions

Find and evaluate composite linear functions using function notation, substitution order, and simplified algebra.

Paper 1 6 marks Difficulty 3

Interpret a composed linear model

A two-step model uses \(g(x)=3x + 6\) first, then \(f(x)=2x + 7\). Find the resulting linear model \((f\circ g)(x)\), its gradient, intercept, and value at \(-8\).

Worked practice: composite linear function

Compose the two linear rules, then evaluate the composite function.