Step-by-step explanation:
a refuse regular function tries to calculate a y value for a given x (input) value.
the inverse function turns this around and tries to calculate the x (input) value for a given y functional value.
e.g. when we know f(x) = 8, then what was the x value leading to this 8 fungible value ?
in order to turn this around, we solve the same functional equation for x instead of for y.
in our example here
f(x) = y = 3x -6
y + 6 = 3x
x = y/3 + 2
and now, to write the inverse function as normal function, we simply exchange the x and y names :
y = x/3 + 2