Relationship for cosine of angle
50277
Relationship between cosines of angles in 4 dimensions
54032
dimensional analysis - how to find the dimensions of a variable inside an angle
135895
Proving the bounds of cosine
155868
How can I find the difference between two angles?
129443
$f(\theta) = \cos \theta - \sqrt{3}\sin \theta$ in the form $r\sin(\theta-\alpha)$
18967
Linear independence of $\sin(x)$ and $\cos(x)$
147886
Proof of the angle sum identity for $\sin$
36628
How do I prove this method of determining the sign for acute or obtuse angle bisector in the angle bisector formula works?
43183
basic geometry angle problem
63679
Picture/intuitive proof of $\cos(3 \theta) = 4 \cos^3(\theta)-3\cos(\theta)$?
67035
History of dot product and cosine
69094
Relationship between $R^2$ and correlation coefficient
59922
If $A = \tan6^{\circ} \tan42^{\circ},~~B = \cot 66^{\circ} \cot78^{\circ}$ find the relation between $A$ and $B$
23321
calculating angle in circle
45584
In $\triangle ABC$ with $AB=AC$ and $\angle BAC=20^\circ$, $D$ is on $AC$, with $BC=AD$. Find $\angle DBC$. Where's my error?
111815
Determine angle $x$ using only elementary geometry
100895
Prove $1 + \cos 2C - \cos 2A - \cos 2B = 4\sin A\sin B\cos C$ for $A$, $B$, $C$ the angles of a triangle