Θ
ρ
ϵ
η
Π
α
τ
π
Trigonometric Functions
Trigonometric Angle Addition Formulas
For any
α
,
β
∈
ℝ
:
cos
(
α
+
β
)
=
cos
(
α
)
cos
(
β
)
−
sin
(
α
)
sin
(
β
)
sin
(
α
+
β
)
=
sin
(
α
)
cos
(
β
)
+
cos
(
α
)
sin
(
β
)
Sine is Odd and Cosine is Even
For any
α
∈
ℝ
:
sin
(
−
α
)
=
−
sin
(
α
)
and
cos
(
−
α
)
=
cos
(
α
)
.