it simple method to determine the Limits of the given function when the x that tend to some number gives u 0/0 when u substitutes in the x variable of the given function. e.g see the above q x is tending to 2 when u substitutes 2 in x variable it gives u 0/0 thus simply u can solve the limit by derivate the numerator and denominator after u do that substitutes 2 and u get the Limit.