Are 5π/3 and -π/3 coterminal? Provide numeric reasoning.

Yes; convert 5π/3 to degrees (300°) and -π/3 to degrees (-60°) then note that 300° + (-60°) = 240° so they are coterminal.

No; because π factors cannot cancel in this pairing.

Yes; their difference is 2π, so they are coterminal.

No; because one is positive and the other negative.