How to determine correct formula for rool, pitch, yaw angle below are the variations I am seeing
X =Roll axis, Y = Pitch axis, Z = Yaw axis
roll_1 = atan(Y / sqrt(X*X + Z*Z))
roll_2 = atan2(Y, sqrt(X*X + Z*Z))
roll_3 = atan(Y/Z)
roll_4 = atan2(Y, Z)
Which one is correct and which to use when.