radians = Math::PI / 4
degrees = 45.0

def deg2rad(d)
  d * Math::PI / 180
end

def rad2deg(r)
  r * 180 / Math::PI
end


puts 

puts 

puts 

arcsin = Math.asin(Math.sin(radians))
puts 

arccos = Math.acos(Math.cos(radians))
puts 

arctan = Math.atan(Math.tan(radians))
puts