Elementary inequalities

Elementary trigonometric inequalities are those of the type $\sin x \ge k$, $\cos x \ge k$, $\tan x \ge k$ (and the analogous ones with $\le$, $<$, $>$). They are solved without calculations, by reading directly on the unit circle which arcs satisfy the condition: the angles above or below a horizontal line for the sine, to the right or to the left of a vertical line for the cosine, and on the axis of tangents for the tangent.

• Elementary inequalities with sine and cosine
• Elementary inequalities with the tangent