Question

Let f(x) = x2 + 6 and g(x) =x+8/x. Find ( g o f)(-7)

Answer 1

can you find the gof ?
gof is the other way though, you plug in what the F(x) is equal to, for x, into the G(x).

When you find Gof, plug in -7 for x, and there will be (gof)(-7).

Answer 2

If something doesn't make sense to you, please ask.

Answer 3

i don't undertstand any of it i'm homeschooled

Answer 4

okay, lets just look at each of the functions separately. Okay?

Answer 5

ok

Answer 6

So lets first see the f(x).
\(\large\color{midnightblue}{ f(x)=x^2+6 }\)

and in this case,
when you want to find f(1)
you plug in 1 for x.

\(\large\color{midnightblue}{ f(x)=x^2+6 }\)
\(\large\color{midnightblue}{ f(1)=1^2+6 }\)
\(\large\color{midnightblue}{ ~~~~~~~=1+6 }\)
\(\large\color{midnightblue}{ ~~~~~~~=7 }\)

So,
\(\large\color{midnightblue}{ f(1)=7 }\)

Answer 7

Can you find f(3) ?

Answer 8

no

Answer 9

can you plug in 3 for x ?

Answer 10

how do i do that... i'm sorry i'm lost

Answer 11

We know that \(\large\color{midnightblue}{ f(x)=x^2+6 }\)
but look what is happening what I try to do f(3)

I replace the x, with the 3.

\(\large\color{midnightblue}{ f(3)=3^2+6 }\)

good so far?

Answer 12

oh ok

Answer 13

can you tell me what f(3) is going to be equal to ?

Answer 14

no

Answer 15

Do you know what it means to say \(\huge\color{midnightblue}{ 3^2 }\) ?

Answer 16

yes

Answer 17

3 times 2?

Answer 18

no

Answer 19

thats how i remember it... thats what my old teacher said

Answer 20

3 times 2 would be
\(\large\color{midnightblue}{3 \times 2 }\)

\(\large\color{midnightblue}{3(2) }\)

\(\large\color{midnightblue}{(3)2 }\)

\(\large\color{midnightblue}{(3)(2) }\)

HOWEVER, \(\large\color{midnightblue}{3^2=3 \times 3=9}\)

Answer 21

wouldmt that be -9

Answer 22

when you say number with a two on top in-front of it, such as

\(\large\color{midnightblue}{3^2=3 \times 3~~~~~~~~~~~~~~=9}\)

or other examples,

\(\large\color{midnightblue}{4^2=4 \times 4~~~~~~~~~~~~~~=16}\)

\(\large\color{midnightblue}{1^2=1 \times 1~~~~~~~~~~~~~~=1}\)

see?

Answer 23

Just 9, not -9. There is no reason for it to be negative, since all you are doing is that you are multiplying 2 positive numbers together. 3 and 3.

Answer 24

oh ok i get the examples now

Answer 25

i just needed the help because i'm on a timer & i couldnt figure it out

Answer 26

So f(3) equals ?

(when \(\large\color{midnightblue}{f(x)=x^2+6 }\) )

Answer 27

ok

Answer 28

tell me (please) what f(3) will be

Answer 29

9

Answer 30

sorry 15?

Answer 31

yes 15.

Answer 32

Can you find
f(-2) ?

Answer 33

no