Joe has a utility function over hamburgers and hot dogs given by U = x + y

Question:

Joe has a utility function over hamburgers and hot dogs given by U = x + √y , where x is the quantity of hamburgers and y is the quantity of hot dogs. The marginal utilities for this utility function are MUx = 1 and MUy = 1/(2√y ). Does this utility function have the property that MRSx,y is diminishing?