Question

given F(x)=\sqrt{(3x-9)}^{3} find f ^{-1}(x)

Answer 1

\[f(x)=(\sqrt{3x-9})^3 \\ y=(\sqrt{3x-9})^3\]
solve for x

Answer 2

how do you solve for x

Answer 3

well first is what I wrote what you mean?

Answer 4

well the first one is but then i have to find f^-1(x)

Answer 5

ok I just wanted to make sure I wrote your function correctly

Answer 6

try raising both sides to (1/3)

Answer 7

we are doing this since 3*1/3 will give us 1

Answer 8

ok so what do we do with the 1

Answer 9

anything to the first power can be written without the exponent
that is u^1=u

Answer 10

okay

Answer 11

when you are ready you can show me what you have after doing that?

Answer 12

\[f^-1x\]

Answer 13

thats supposed to be srrt -1x

Answer 14

\[y=(\sqrt{3x-9})^3\]
so asked you to raise both sides to (1/3)
so you should have had this:
\[y^\frac{1}{3}=(\sqrt{3x-9})^{3 \frac{1}{3}} \\ y^\frac{1}{3}=(\sqrt{3x-9})^1 \\ y^\frac{1}{3}=\sqrt{3x-9}\]
but I don't even you tried doing that based on what you have there :(

Answer 15

anyways square both sides not so you can undo that radical part that contains the x thingy majigger

Answer 16

i thought you meant replace the square root im sorry

Answer 17

square both sides so you*

Answer 18

no I didn't say that
I said to raise both sides to (1/3) power

Answer 19

yeah i misunderstood

Answer 20

ok do you want to try squaring both sides ?

Answer 21

another way to say that is raise both sides to second power
(we are trying to undo the square root thing)

Answer 22

okay i have to log off but i get what your saying and i understand it so thank you

Answer 23

ok cool
your main objective is to solve for x
and then you can interchange the variables at the end

Answer 24

but later and good luck @kimdarlene

Answer 25

thank you and you to