Question

Find the function value.
f(x)=x^3
f(-9)=___

Answer 1

ok so its asking you this: f(when x is 9) = \[x^{3}\]

Answer 2

what does x^3 equal when x=9

Answer 3

yes..

Answer 4

or -9

Answer 5

3?

Answer 6

so whats the problem?

Answer 7

-9, sorry

Answer 8

so can you compute this?

Answer 9

i am not sure, first time taking algebra 1

Answer 10

\[f(a)=a^3\]
\[f(5)=5^3\]
so
f(-9)=?

Answer 11

Myininaya..now i am confused!

Answer 12

where does the 5 come from?

Answer 13

its an example

Answer 14

oh, ok..

Answer 15

\[f(6)=6^3\]
\[f(-6)=(-6)^3\]

Answer 16

ok something cubed looks like \[ a^{3} = a\times a \times a\]

Answer 17

f is like a maching
you are putting a number into that machine
and you are getting the input cubed back

Answer 18

machine*

Answer 19

so \[x^{3} = x \times x \times x \]

Answer 20

now let each x = -9 and multiply that together.

Answer 21

so i would multiply-9 *3?

Answer 22

27

Answer 23

-27

Answer 24

wait, I never said there was a three involved, did I?

Answer 25

no

Answer 26

\[(-9)^3\]

Answer 27

\[(-9)^3 \neq -9 \cdot 3\]

Answer 28

if you were to let each of those x's that i wrote out earlier what would that look like when you substitute them in?

Answer 29

let each of those = 9 i meant.

Answer 30

-9*

Answer 31

just like myininaya did, thats what i meant..

Answer 32

\[\text{ what is } (-9)^3 \text{?}\]

Answer 33

9*3=27

Answer 34

no

Answer 35

yes -9 is correct so let me start it for you f(-9) = \[-9 \times -9 \times ? \]

Answer 36

what else goes there to finish what i wrote out before?

Answer 37

example:
\[a^3=a \cdot a \cdot a\]
\[5^3=5 \cdot 5 \cdot 5 =25 \cdot 5 = 125\]

Answer 38

-9x-9x-9=729

Answer 39

almost

Answer 40

wait what is -1 x -1 ?

Answer 41

a negative times a negative times a negative =?

Answer 42

-1

Answer 43

\[-1 \cdot -1=1\]

Answer 44

\[-1 \cdot -1 \cdot -1=1 \cdot -1 =?\]

Answer 45

ugh, i get mixed up with these negatives..sorry for being difficult

Answer 46

-1 * -1 = ? then whatever ? is needs to be multiplied by -1 so ? * -1 = your sign answer

Answer 47

so f(-9)=9

Answer 48

sorry, still confused, and this is probably a simple problem and I am just not getting it

Answer 49

wait what happened? i thought you got the correct solution above but just the wrong sign?

Answer 50

am i suppost to put a negative before the 729.....-729?

Answer 51

you need to re-read what we talked about above and decide for yourself...ask any questions you have about clarity but just re-read what is above the answer is there!

Answer 52

wasn't getting it but thanks.

Answer 53

ok, so moses, this i show i understood it
-9*-9=81*-9=-729

Answer 54

you are intelligent!!!!

Answer 55

good job that is right!

Answer 56

thanks again..i had to read it twice. I think what confused me more is when the other person came on here and it really through me off..so sorry for the confusion

Answer 57

it is -729