Select all irrational numbers.
√1/4
√2/4
√3/4
√4/4
√5/4

All but √4/4 are irrational because the definition of an irrational number is a number that is never ending like pi, or a number that cannot be converted to a fraction. √1/4 is irrational because when you find the square root, it comes out with a number that is near impossible to convert to a fraction because it is a never ending decimal.

Do you need with the x value for the minimum? its always between the two intercepts for a parabola