Question 431626
if it is, you just need to find a number such that the number squared = 1/36

let, a = (1/6), then a^2 = (1/6)^2 = (1^2/6^2)=(1/36)

of course if you let b = -(1/6), you will get the same result, so yes, it is a perfect square, and we know this is true since we have found numbers a and b, such that a^2 and b^2 = (1/36)

conversely if a number was not a perfect square, then if we try to take it's square root we will find it is not a rational number, and therefore not a perfect square