Concept — Coseno. Featured in chapters 28 Linked atoms 12 linked atoms. 28 Circonferenza goniometrica e funzioni sin, cos, tan Arcs differing by pi Complementary arcs Domain, range and sign Graphs of sine and cosine Notable values Opposite arcs Periodicity Sine, cosine and tangent of an arbitrary angle Supplementary arcs The fundamental identity The ladder leaning against the wall Values using associated arcs