What differs the trigonometric equation and inequality from others is that they have trigonometric functions of the unknowns.
Trigonometric function is the relationship made between the sides and angles of a right triangle. These relations are called sine, cosine, tangent, cosecant, secant, cotangent.
►See some examples of when an equation is trigonometric and when it is not trigonometric.
sin x + cos y = 3 is a trigonometric equation, since the unknowns x and y have trigonometric functions.
x + tg30º - y2 + cos60º = √3 is not a trigonometric equation, because the trigonometric functions do not belong to the unknowns, that is, the unknowns are independent of the trigonometric functions.
►See now examples of trigonometric inequalities and when an inequality is not trigonometric because it has trigonometric functions.
sin x > √3 is a trigonometric inequality because a trigonometric function is a function of an unknown.
(sin 30°). x + 1 > 2 is not a trigonometric function, since a trigonometric function is not a function of the unknown.
by Danielle de Miranda
Graduated in Mathematics
Brazil School Team
Trigonometry - Math - Brazil School
Source: Brazil School - https://brasilescola.uol.com.br/matematica/equacao-e-inequacao-trigonometrica.htm