Even And Odd Functions
cos(x) is even, sin(x) is odd
COS(X+Y)
cos(x) cos(y) - sin(x) sin(y)
+
+
COS(X±Y)
cos(x) cos(y) ∓ sin(x) sin(y)
+
+
Relations Around π/2
sin or cos of π/2 ± x
+
+
SIN(X±Y)
sin(x) cos(y) ± cos(x) sin(y)
+
+
Relations Around π
sin or cos of π ± x
+
+
TAN(X±Y)
+
+
2X Relations
sin(2x), cos(2x)
+
Sum And Difference Of Cosines
cos(x) ± cos(y)
+
Sum And Difference Of Sines
sin(x) ± sin(y)