IB skill practice

Solve functional equations

Use structure and substitution to solve functional equations.

Paper 1, Paper 2 5 marks Difficulty 4

Solve functional equations - visual endpoint link

If \(f(x+y)=f(x)+f(y)\), \(f(1)=5\), and \(n=3\), enter \(f(n)\).

Worked practice: result and interpretation

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