Question

simplifique :
sen ( pi + x )

Answer 1

pi=x
x=pi
entao da isso ai

Answer 2

$Sen(\pi + x) = sen(\pi).cos(x) +sen(x).cos(\pi) \\ \\ Sen(\pi + x) = 1.cosx + sen(x).0 \\ \\ Sen(\pi + x) = cos(x)$