maths.free › Trigonometry

Trigonometry

Angles, the unit circle, identities and trig equations.

Nhazi

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.

Nkuzi ndị ọzọ

Otú ụfọdụ n'ime ihe ọmụmụ ndị a si agbanwe site n'akwụkwọ ndị mepere emepe: OpenStax Algebra and Trigonometry 2e, OpenStax Precalculus 2e, Wikipedia. Ihu ebe ọbụla na-akpọ isi ya na ikikembanye ya.

Aịkọn ndị ahụ ejirila ebe a

Tinye ọbụla simbụl maka nkọwa zuru ezu, inyogo, na ihe ọbụla ọbụla na-egosi.

Ajụjụ ndị mmadụ jụrụ

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.

Ị nwere nsogbu nke onwe gị?
Tinye ya mọọbụ depụta ya na ihuakwụkwọ onyenhọrọ ihenhọrọ: nzọụkwụ ọbụla, inyogo, azịza echekwara ruo mgbe ịjụla.
Wepụ →

Ụlọọrụ ndị ọzọ