Question

If f(x)=7x-12, what is f^1(x)

Answer 1

easiest method is to write
\[y=7x-12\] then switch x and y ( because that is what the inverse does) to get
\[x=7y-12\] and solve for \(y\)

Answer 2

actually real easiest method is to think.
what does \(f\) say to do?
1) first multipliy by 7
2) then subtract 12

how do you undo this?
1) first add 12
2) then divide by 7

so your function says to do that, and can be written as
\[f^{-1}(x)=\frac{x+12}{7}\]

Answer 3

Thank you!

Answer 4

like if you were solving
\[7x-12=50\] for x, what would you do?
add 12
divide by 7

yw