Notable values

Some angles recur so often that it is worth knowing by heart their values of sine, cosine and tangent.

In brief — Table of notable angles

	$0$	$\pi/6$	$\pi/4$	$\pi/3$	$\pi/2$
$\sin$	$0$	$\tfrac{1}{2}$	$\tfrac{\sqrt{2}}{2}$	$\tfrac{\sqrt{3}}{2}$	$1$
$\cos$	$1$	$\tfrac{\sqrt{3}}{2}$	$\tfrac{\sqrt{2}}{2}$	$\tfrac{1}{2}$	$0$
$\tan$	$0$	$\tfrac{\sqrt{3}}{3}$	$1$	$\sqrt{3}$	$\nexists$

These values are obtained from the properties of the notable triangles already seen in Year Two: the equilateral triangle (for $\pi/6$ and $\pi/3$) and the isosceles right triangle (for $\pi/4$).

Links

Topics: Trigonometry
Concepts: Notable angles · Cosine · Sine · Tangent
Functions: Cosine · Sine · Tangent
Skills: Using formulae