Question

inverse of f(x)=2x-4?

Answer 1

did you get the last one?

Answer 2

no

Answer 3

there was an error, so check it. then do this one the same way

Answer 4

i dont undeerstand!

Answer 5

\(\Large \color{midnightblue}{\rightarrow f^{-1}(x) = {x + 4 \over 2} }\)

Can anyone explain me too?

Answer 6

if you did not get the last one, then you need to work with the people who are trying to help you learn it.

Answer 7

Am I right?

Answer 8

@jabbers! Let's learn together.

Answer 9

kk

Answer 10

1) Add 4
2) Divide by 2.

Answer 11

k

Answer 12

I am not sure, we'll have to check.

Answer 13

k

Answer 14

I'll probably just repeat what satellite has said, but...
let y=f(x)

we then have

y=2x-4

solve for x, then switch the places of x and y
the new expression for y is the inverse f^(-1)

Answer 15

easiest method is to write
\[y=2x-4\]switch x and y because that is what the inverse function does and write
\[x=2y-4\] and then solve for \(y\) via
\[x=2y-4\]
\[x+4=2y\]
\[y=\frac{x+4}{2}\] so
\[f^{-1}(x)=\frac{x+4}{2}\]

Answer 16

ok i understand. thanks!

Answer 17

eyeball method also works
your function says
1) multiply by 2
2) subtract 4

inverse will say
1) add 4
2) divide by 2

you write this as
\[f^{-1}(x)=\frac{x+4}{2}\]

Answer 18

@satellite73 Why is it another variable?

Answer 19

not sure what you are asking.
we usually write functions as a function of x, but the variable is unimportant, only the action matters. we could write
\[f^{-1}(x)=\frac{x+4}{2}\] or
\[f^{-1}(y)=\frac{y+4}{2}\] or
\[f^{-1}(\zeta)=\frac{\zeta+4}{2}\] or even
\[f^{-1}(\spadesuit)=\frac{\spadesuit +4}{2}\]

Answer 20

lol

Answer 21

Why do we get this equation? --->

2y + 4 = x

Answer 22

if i recall correctly indian mathematicians where the first to use variables, and they used colors

Answer 23

\(\Large \color{midnightblue}{\rightarrow f^{-1}(x) = f(y) }\)

Right?