Question

f(x) = sqrx+8; g(x) = 8x - 12

Find f(g(x)).

Answer 1

I can help.

Answer 2

You remember how when it was simple, we would be given a function f(x)=x+10, where we would find f(2)=2+10?

Answer 3

3rd one

Answer 4

This is quite similar. For f(g(x)), our 'x' in our f(x), we will putin function g(x)

Answer 5

It looks like this...
22x−1−−−−−√

Answer 6

f(x) = sqrx+8; g(x) = 8x - 12

Find f(g(x)
f(x)=sqrt (x+8) = g(8x-12)= sqrt (8x-12+8)

Answer 7

@mjmahmood You're a little off.

Answer 8

@mjmahmood Maddy is helping me and you're just trying to give me the answer. I want to learn how to solve it.

Answer 9

f(g(x)) = sqrt (8x-12+8), where now you just combine the 12 and 8 at the end.

Answer 10

Do you have answer choices to this?

Answer 11

pretty sure its f(g(x)) = sqrt (8x-4) if I combined the 12 and 8 correctly.

Answer 12

These are my choices

Answer 13

Ah. I'm thinking A.

Answer 14

Wait

Answer 15

No, maybe C. My bad.

Answer 16

Not sure how the square root could have that power of 8. I haven't learned of that.

Answer 17

We usually always have 3 or 2, but having that 2 with answer choice c specifically should be the answer.

Answer 18

It wants you to simplify the (8x-4) because that is not in simplest form.

Answer 19

This is precal but it's supposed to be stuff I learned a long time ago I just forgot it :/

Answer 20

Don't worry I am in pre-calc too, I am surprised at how much I have to try to remember.

Answer 21

I know it's not b. I mean, considering the way you gave me the function, it shouldn't be.

Answer 22

D doesn't make sense with the function given.

Answer 23

And C matches the actual simplified form of what would be 8x-4. Given radical properties and blah blah blah

Answer 24

Unless, my math is wrong. But I wrote it out. It's whatever you think is right. (-:

Answer 25

I'm trying to work it out... lol Really appreciate your help :)
I don't doubt you're right just need to figure out why so i can do it no problem in the future..

Answer 26

Understandable. I am the same way! It's basically finding which is the simplified form of 8x-4. I am searching stuff now to help.

Answer 27

http://math.stackexchange.com/questions/466049/what-does-the-small-number-on-top-of-the-square-root-symbol-mean

Answer 28

f(sqr(x+8)) = 8(sqr(x+8)) - 12 is what we're trying to solve, right?

Answer 29

f(x) = sqrx+8; g(x) = 8x - 12

Find f(g(x)
f(8x-12)= sqrt (8x+8-12) = sqrt (8x-4) is what I get

Answer 30

I'm totally getting backwards lol sorry about that

Answer 31

Thats okay (-:

Answer 32

I can' see or understand why it the radical would have the compendium of 8 that doesn't make sense to me, not for those functions.

Answer 33

2^3=8 so 3^sqrt(8)=2.

Answer 34

And having it be 8^sqrt would produce pretty large numbers.

Answer 35

This is what I think

Answer 36

8x-4 lets set that to f(x)

Answer 37

Then we could maybe set that to y=8x-4. Uhm. Divding it by 4 to both sides gives y=2x-1

Answer 38

f(x)= sqrt 2x-1

Answer 39

C is your answer.Just figured it out!

Answer 40

Because to simplify y=8x-4, we can put 4 into 8x and -4.

Answer 41

Or keep it f(x). I set to y because it makes any calculations easy.

Answer 42

So for this, C is your answer.

Answer 43

Thank you :) I just to find out how it simplifies

Answer 44

Me too. I was trying to think of a way to simplify 8x-4 because it wasn't in simplest form. Then it dawned on me ' oh silly, set it to just f(x)=8x-4 and divide by 4 cause thats the common greatest factor between the two '
Which then yields 2x-1. So that only proves C to be correct, and probably after you apply 2^sqrt to 2x-1 you should get an equation similar or equal to 8x-4.

Answer 45

I found it: since 8 is not a square we need to break it into 2*4x - 4 which simplfies to 2sqr2x-1 (the imaginary number is sqr-1 * sqr4 and I guess gets lumps with the 2 on the outside of the radical)

Answer 46

http://algebralab.org/lessons/lesson.aspx?file=Algebra_radical_simplify.xml

Answer 47

Great work there @OnePieceFTW ! :)

Answer 48

Thank you :) Really appreciate the help!

Answer 49

Makes sense now, cause then times it by 2 gives 4 which then can be squared, etc.

Answer 50

Anytime! I think we each learned something, that's what math is about.