cos²(x)+sin²(x)
1
tan²(x)+1
sec²(x)
cot²(x)+1
csc²(x)
cos(a+b)
cos(a)cos(b)-sin(a)sin(b)
cos(a-b)
cos(a)cos(b)+sin(a)sin(b)
sin(a+b)
sin(a)cos(b)+cos(a)sin(b)
sin(a-b)
sin(a)cos(b)-cos(a)sin(b)
sin(2x)
2sin(x)cos(x)
cos(2x)
1-2sin²(x)
cos²(x)-sin²(x)
2cos²(x)-1
cos²(x)
(1+cos(2x))/2
sin²(x)
(1-cos(2x))/2
sin(x/2)
sqrt((1-cos(x))/2)
cos(x/2)
sqrt((cos(x)+1)/2)