Trygonometric Numbers .
Angles : ω , x & ω+x=90 degrees => x=90-ω
sin(90degrees - ω)= cosω
cos(90degrees - ω)= sinω
tan(90degrees - ω)=cotω cot=cos/sin
cot(90degrees - ω)=tanω
For example
sin60= sqrt3/2 cos(90-60)=cos30=sin60=sqrt3/2
cos60=1/2 sin(90-60)=sin30=cos60=1/2
tan60=sqrt3 tan(90-60)=tan30=cot60=sqrt3/3
cot60=sqrt3/3 cot(90-60)=cot30=tan60=sqrt3















