Function — Coseno.
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63 linked atoms.
28 Circonferenza goniometrica e funzioni sin, cos, tan
- Arcs differing by pi
- Complementary arcs
- Domain, range and sign
- Fundamental identity with complementary arcs
- Graphs of sine and cosine
- Notable values
- Opposite arcs
- Periodicity
- Sine, cosine and tangent of an arbitrary angle
- Supplementary arcs
- The fundamental identity
- Values using associated arcs
29 Formule di addizione, duplicazione, bisezione
- 3
- Example: cosine of 15°
- Example: cosine of 75°
- Example: linearising sin⁴α
- How the other formulae are derived
- Linearising sin²α cos²α
- Lowering the degree: linearisation formulae
- Proof of the bisection formulae
- Proof of the cosine subtraction formula
- Sine of 105° and cosine of 165°
- The addition and subtraction formulae
- The bisection formulae
- The duplication formulae
- Triple-angle formula for the cosine
30 Formule parametriche, prostaferesi, Werner
- Difference to product with sum-to-product formulae
- Equation with sum-to-product formulae
- Expression with parametric formulae
- Factorising a sum into a product
- Identity on the three angles of a triangle
- Linear equations in sine and cosine
- Product to sum with Werner
- Sum-to-product formulae: from sum to product
- The parametric formulae
- Werner formulae: from product to sum
- When to use what
31 Equazioni goniometriche
- Definition and solution method
- Elementary equation in cosine
- Elementary trigonometric equations
- Equation with sum-to-product formulae
- Equations reducible to homogeneous ones
- Equations solvable by substitution
- Linear equation with two methods
- Reading on the trigonometric circle
- Second-degree homogeneous equation
- The auxiliary-angle method
- The parametric-formulae method
32 Disequazioni goniometriche
- Absolute value of the cosine
- Elementary inequalities with sine and cosine
- Factorisation with the double-angle formula
- Inequality reducible to the cosine
- Product of factors and sign table
- Product of factors with sign table
- The sign-study method
33 Trigonometria dei triangoli
- Angle from three sides
- Proof of the law of cosines
- Solving a triangle with the law of cosines
- The law of cosines
- Trigonometry in right-angled triangles