有谁知道特殊三角形的三角函数值,即正弦,余弦,正切,余切.

sin 0° = 0
cos 0° = 1
tan 0° = 0
cot 0° = + ∞
sin 30° = 1/2
cos 30° = √3/2
tan 30° = √3/3
cot 30° = √3
sin 45° = √2/2
cos 45° = √2/2
tan 45° = 1
cot 45° = 1
sin 60° = √3/2
cos 60° = 1/2
tan 60° = √3
cot 60° = √3/3
sin 90° = 1
cos 90° = 0
tan 90° = + ∞
cot 90° = 0