maths.free › Trigonometry

Trigonometry

Angles, the unit circle, identities and trig equations.

Zikumbutso

Trigonometry is the geometry of the circle written as functions. Exact values from the unit circle, equations with infinitely many solutions, and the identities that make them tame.

Maphunziro ena

Ena mwa maphunzirowa anawapanga pogwiritsa ntchito mabuku otsegulira: OpenStax Algebra and Trigonometry 2e, OpenStax Precalculus 2e, Wikipedia. Patsamba lililonse la maphunziro pali dzina la m’badwo wake ndi lisensi yake.

Zithunzi

Pitani pa dzina lililonse lachifaniziro kuti mudziwe tanthauzo lake, chithunzi chake, ndi zimene limatanthauza.

Mafunso omwe anthu amafunsa

Why radians instead of degrees?

A radian is the angle whose arc equals the radius, so it is a pure ratio rather than an arbitrary 1/360 of a turn. With radians the derivative of sin x is exactly cos x; with degrees a factor of π/180 appears everywhere.

Why does sin x = 1/2 have infinitely many solutions?

Sine repeats every full turn, and within one turn it reaches 1/2 twice (at π/6 and 5π/6). Add any whole number of turns to either and it is still true.

How do I remember the exact values?

Two triangles: the 45-45-90 with sides 1, 1, √2 and the 30-60-90 with sides 1, √3, 2. Every value for 30°, 45° and 60° is a ratio of those sides; symmetry gives the rest of the circle.

Kodi muli ndi vuto lanu lokha?
Tiyeni tiwone ngati tingathe kufotokoza bwinobwino zimene zikuchitika patsamba la solver: panthawi iliyonse, chithunzi, yankho limakhala lofiira mpaka mutafunsa.
Kuchotsa →

Mabungwe ena