Question

Please help me solve this.

f-1(3) when f(x) = 2x plus 3, all over 5

Answer 1

To find the inverse:

Replace f(x) with y
Switch x's and y's, so put x where y is and x where y is.
Solve for y
Replace y with f^-1(x)

Answer 2

Once you find the inverse plug in 3 for the function.

Answer 3

what?>>

Answer 4

\[f(x)=(2x+3)^5?\]

Answer 5

Ok, so follow my steps I have put and see what you get for the inverse first.

Answer 6

so you put a y where the x is?

Answer 7

Yeah you interchange them

Answer 8

take f(x)=3

Answer 9

find x

Answer 10

substitube for y

Answer 11

then subtitute in the main equation

Answer 12

so 2(3)+3 / 5?

Answer 13

no no

Answer 14

@iambatman U take this

Answer 15

Sorry im really trying to get this its my second to last question in this class ever

Answer 16

Let f(x)=y

Answer 17

\[f(x) = \frac{ 2x+3 }{ 5 } \implies y = \frac{ 2x+3 }{ 5 }\]
No worries, I think he just confused you more, so just follow the steps I gave you, now interchange.

Answer 18

Did that part deal with the f^-1?

Answer 19

What part? We haven't gotten there yet, all we did was let f(x) = y

Answer 20

okay. So what do i do after that?

Answer 21

Now we switch x's and y's

Answer 22

So put x's where the y is and put y where the x is.

Answer 23

oh this is like a 2 part problem, you solve it twice kinda thing?

Answer 24

for one you solve for x and the other you solve for y?

Answer 25

I guess you can think of it that way :)

Answer 26

Well, not quite

Answer 27

You're just switching the variables and solving for y, and then letting it equal f^-1(x)

Answer 28

im lost sorry

Answer 29

Try doing the problem, with the steps I gave you earlier, and if you want more detail in what exactly a inverse function is, just read this: http://www.mathsisfun.com/sets/function-inverse.html

Answer 30

okay i kinda get it now

Answer 31

DUDE I didnt mean to confuse u more man.....lol

Answer 32

you didn't. I didn't understand it in the first place. Im doing algebra 2 when ive just started algebra 1