Answer:
Step-by-step explanation:
Cos(pie/2)
Pie is π
This shows that the π is in radian
2πrad= 1 complete revolution
2πrad= 360°
Divide both side by 2
πrad=180°
So let substitute πrad=180° into the cosine
Cos(π/2)=Cos(180/2)
Cos90
Cos 90 is zero
Cos(pie/2)=0
