Explain why this sequence of steps is incorrect.

Question

log₃121= log₃[(-11)(-11)]

= log₃(-11) +log₃(-11)

Answer 1

The domain of the log function is (0,∞)

So, the use of logarithm rules is correct, but log₃(-11) is undefined.

You could do the same steps, but factor 121 into (11)(11) instead.