Functions
Mathematical notation, domain and range, composition and inverse functions, and the graphs of the elementary functions. Functions is tested in the Mathematics section of the Bocconi Test, which has 24 of the 50 questions (75 minutes in total, 2027/28 format). This guide covers it in 7 lessons, each with the rule that solves it and a diagram.
Mathematical notation
Read the symbols precisely: ∈ “belongs to”, ⊂ “is a subset of”, ∀ “for every”, ∃ “there exists”, ⇒ “implies”, ⇔ “if and only if”. Σ adds a pattern and n! multiplies 1 to n.
What a function is
A function gives every input exactly one output. f(x + 1) means writing x + 1 wherever x was. A graph is a function if no vertical line meets it twice.
Domain
The domain is every x where the formula makes sense: denominators ≠ 0, even roots of numbers ≥ 0, logarithms of numbers > 0. Write each condition, then intersect them.
Composition of functions
(f ∘ g)(x) = f(g(x)): apply g first, then f. The order matters, and x must be in the domain of g with g(x) in the domain of f.
Inverse functions
Only a one-to-one function has an inverse. Swap x and y, then solve for y. The graph of f⁻¹ is the mirror image of f in the line y = x, and domain and range swap.
Graphs of the elementary functions
Know the shapes of x, x², x³, √x, 1/x and |x| by heart: where each is defined, where it rises or falls, its symmetry and the points (0, 0) and (1, 1).
Transforming graphs
f(x) + k moves the graph up by k; f(x − h) moves it right by h; −f(x) reflects it in the x-axis and f(−x) in the y-axis; |f(x)| folds the part below the axis upwards.
What is the Bocconi Test format?
Online Bocconi Test for admission in academic year 2027/28, as published by Università Bocconi.
- Questions / time
- 50 / 75 minutes
- Distribution
- 24 mathematics · 11 reading · 6 numerical reasoning · 9 critical thinking
- Scoring
- +1 correct · 0 blank · −0.2 wrong
- Question languages
- English · Italian
- Three-option questions
- Some critical thinking questions have three options; a wrong answer there costs −0.33
- Minimum score
- Below 17 points the test is not considered for selection
- AI degree
- Mathematical and Computing Sciences for Artificial Intelligence also needs at least 11 of 24 points in mathematics
- Law test
- A separate test, 50 questions / 75 minutes: 5 mathematics · 11 reading · 6 numerical reasoning · 18 logic and critical thinking · 10 verbal reasoning; same scoring
Source: Università Bocconi, Online Bocconi Test page (checked October 7, 2026)
Practise this topic
Take the free diagnostic to see where this topic sits against the other 47, then work through the question bank.
Start the free diagnostic