Answer:

inverse

Answer	Crossword Clue
INVERSE	Reciprocal
INVERSE	Wrong side out
INVERSE	Opposite

INVERSE	Division, vis- -vis multiplication
INVERSE	Direct opposite
INVERSE	Turned upside down
INVERSE	Counter
INVERSE	Opposite.
INVERSE	Directly opposite.
INVERSE	2, to 1-2
INVERSE	Trig calculation

INVERSE	1-3, to 3