Metamath Proof Explorer


Theorem sinhalfpi

Description: The sine of _pi / 2 is 1. (Contributed by Paul Chapman, 23-Jan-2008)

Ref Expression
Assertion sinhalfpi ⊢ sin ⁡ π 2 = 1

Proof

Step Hyp Ref Expression
1 sinhalfpilem ⊢ sin ⁡ π 2 = 1 ∧ cos ⁡ π 2 = 0
2 1 simpli ⊢ sin ⁡ π 2 = 1