Question

CHECK MY ANSWER! I GOT A

Answer 1

Where is the question?

Answer 2

You might want to zoom in so people can see it :/

Answer 3

click it dude

Answer 4

@phi

Answer 5

Did you try my test ?

Answer 6

one way to check:
in the first equation put in x=0 and you get out y=2
in the 2nd equation put in x=2 and if it's an inverse, you should get out y=0
(0,2) --> (2,0)
but notice if you put in 2 in the 2nd equation you get 4/3 and that is not 0

Answer 7

ok let me try that

Answer 8

@phi ... I tried it again I got B again because I got a -8x+3

Answer 9

I sub i the same values right?

Answer 10

in the first equation, if you put in x=0 what do you get ?

Answer 11

9

Answer 12

are you using
\[ f(x) = 8x^3 + 1 \]
?

Answer 13

I did 8(0)^3 +1

Answer 14

ok and 8*0*0*0 + 1 is what ?

Answer 15

1

Answer 16

that's better you got (0,1) now we test do we get (1,0) in the other equation
in other words, put in 1. do you get 0 ?

Answer 17

use
\[ g(x) = \sqrt[3]{x-8} \]
with x=1
do you get 0 out ?

Answer 18

no u dont

Answer 19

so they are not inverses.

Answer 20

so i was right

Answer 21

btw, if you have time, it's good practice to try to find the inverse of f(x)
write it
\[ y= 8x^3 + 1\\ \text{ swap x and y } \\ x= 8y^3 + 1 \\ \text{ solve for y} \\
\]
\[ x - 1 = 8y^3 \]
\[ \frac{x-1}{8} = y^3 \\
\sqrt[3]{\frac{x-1}{8}} = y\]

Answer 22

if you use the correct equation and you put in x=1 what do you get out ?

Answer 23

8

Answer 24

use this one
\[ y = \sqrt[3]{\frac{x-1}{8}} \]
put in x=1

Answer 25

1-1 = 0 .... 0/8 =0

Answer 26

and the cube root of 0 is also 0
so using the correct inverse equation we got (0,1) and (1,0)

Answer 27

if we used x=1 in the first equation we would get (1,9)
and the 2nd equation (i.e. the correct inverse) would give us (9,1)

Answer 28

Awesome its a no with that as-well then right

Answer 29

That was another example of what a correct function/ inverse function would do
if you put in x in the first equation and get y i.e. have (x,y) as the pair
then the inverse function should work with (y,x)

notice (0,1) and (1,0) or (1,9) and (9,1)

Answer 30

but Q8 is *not* an inverse. because we get (0,1) and (1, not 0)
(some ugly number)