Question

Find the inverse of f(x) for f(x) = -3x +2 and state whether or not it is a function.
a.
inv f(x) = -(1/3)x + 2/3; function
c.
inv f(x) = (1/3)x + 2/3; function
b.
inv f(x) = (1/3)x - 2/3; not a function
d.
inv f(x) = -(1/3)x - 2/3; function

Answer 1

Let
\[y=-3x+2\]
Then,
\[3x=-y+2\]
\[x=-1/3y+2/3\]
Therefore,
\[f ^{-1}(x)=-1/3x+2/3\]
The answer is option (a).
This is a function