Question: What is Exponential function opposite of and what is its image function?
Paraphrase: Name an opposite of an exponential function, in addition to its image function.
SPARQL (Wikidata): SELECT ?ans_1 ?ans_2 WHERE { wd:Q168698 wdt:P461 ?ans_1 . wd:Q168698 wdt:P2396 ?ans_2 }
Answer: logarithm, set of positive real numbers