Question

Translation:Explain the behavior of f(x)= ln (x-a) when x=a. Give values to x and a such that x-a=0

Answer 1

when x = a

we have ln(x-a) = ln(0)

ln(0) is undefined in the real number system. By using the extended real number system, we get that ln(0) equals negative infinity. Infinity does not exist in the set of real numbers.