Please help!! Determine whether the following function is a one-to-one function. If it is one-to-one, list the inverse function by switching coordinates, or inputs and outputs.
f = {(9,7), (7,9), (6,7)}

The function is one-to-one. The inverse is f 1 = {(7,9), (9,7), (7,6)}.
The function is one-to-one. The inverse is f 1 = {(-7, -9), (-9, - 7). (-7, -6)}.
The function f is not a one-to-one function.
The function is one-to-one. The inverse is f 1 = {(-9,7), (-7,9), (-6,7)}.