Database
BASIC REAL AND COMPLEX FUNCTIONS
Basic trigonometry
Properties of pi = 3.14159...
halfpire
Next ⟩
neghalfpire
Metamath Proof Explorer
Ascii
Unicode
Theorem
halfpire
Description:
_pi / 2
is real.
(Contributed by
David Moews
, 28-Feb-2017)
Ref
Expression
Assertion
halfpire
⊢
π
2
∈
ℝ
Proof
Step
Hyp
Ref
Expression
1
pire
⊢
π
∈
ℝ
2
1
rehalfcli
⊢
π
2
∈
ℝ