Question

Let f(x) =x+3 and g(x) =4x. Find f(g(2))

Answer 1

plug the result of g(2) into f(x)

Answer 2

so x=2?

Answer 3

yeah

Answer 4

f(2)= 2+3 and g(2)=4(2)?

Answer 5

we're not touching f(x)
in function composition \(f(g(x))\) means evaluating \(g(x)\) and plugging the result into \(f(x)\).

first find g(2). you say it's 4(2). looks right

Answer 6

do i solve that or no?

Answer 7

well, yeah...

Answer 8

ok, 6.

Answer 9

not exactly

Answer 10

then what do you mean?

Answer 11

i'm confused.

Answer 12

you're multiplying not adding. \(4(2)=4 \times 2\)

Answer 13

omg blonde moment!! 8

Answer 14

I can't wait till I'm fully bald so that I can make blonde moment jokes that have 2 layers

Answer 15

so now we have to evaluate f(8)

Answer 16

hahahahahah
and what does that mean?

Answer 17

I don't understand how little you know about functions. If I asked you what the value of f(2) is what would you say?

Answer 18

that sounds mean
I meant I don't know where to start explaining if I don't know what you don't know

Answer 19

ya know?

Answer 20

i have no clue how do do any of this

Answer 21

a function takes a value and outputs another value. there are other technicalities but that's the basic definition we need here.

here, \(f(x)=x+3\), right?
that means wherever we see an x, we replace it with the number we're plugging into the function to evaluate.

for example: \(f(x)=x+3\\f(2)=2+3\\f(5)=5+3\) etc.