Question

let f(x)=│x-3│ which of the following conditional statement hold true
A.f(x)=-(x-3)
B.f(x)0 if x=0
C.f(x)=x-3 if x>0
D.f(x)=x-3 if x>3

Answer 1

@satellite73 can u help

Answer 2

if f(x)=|x|
then
f(x)=x ,when x>0
f(x)=-x,when x<0
use this property

Answer 3

can u help me solve it

Answer 4

consider x is 5

is A correct?

Answer 5

yea

Answer 6

check that

f(x)=│x-3│
f(5)=│5-3│
= ?


A. f(x)=-(x-3)
f(5)=-(5-3)
= ??


are ? and ?? equal

Answer 7

ohh

Answer 8

what do you get for ? and ??

Answer 9

im trying to figure it out

Answer 10

can u help me

Answer 11

f(5)=│5-3│



what is 5-3

Answer 12

2

Answer 13

f(5)=│5-3│
= | 2|


what is absolute value of 2

Answer 14

2

Answer 15

good so

f(x)=│x-3│
f(5)=│5-3│
= | 2 |
= 2


A. f(x) = -(x-3)
f(5) = -(5-3)
= -(2)


are 2 and -(2) equal? could A. be correct?

Answer 16

no

Answer 17

good, so we can rule out option A.

Answer 18

ok

Answer 19

lets look at option B. now

f(x)=│x-3│

B. f(x) = 0 if x=0


lets compute f(0)

f(0) =│0-3│
=


what does this simplify to become?

Answer 20

3

Answer 21

thats right f(0) = 3 is this that same as B. f(x) = 0 if x=0 ?

Answer 22

yea

Answer 23

3 is the same as 0?

Answer 24

oh noo

Answer 25

3 and 0 are not the same are they, so can option B. be the correct one?

Answer 26

no

Answer 27

f(x)=│x-3│

How about option C.

C. f(x) = x-3 if x>0

lets try x = 7 because 7>0

what is f(7) =

Answer 28

7

Answer 29

f(7) =│7-3│
= . . .

Answer 30

4

Answer 31

ok and

C. f(7) = 7-3
= . . .

Answer 32

4

Answer 33

that's right so we tested x=7 and found no problem with C.
but what if we tested x = 2 because 2 is still greater than zero


f(x) =│x-3│
f(2) = | 2-3 |
=

C. f(x) = x - 3
f(2) = 2 - 3
=


are these the same?

Answer 34

yes

Answer 35

what did you get for

f(2) = | 2-3 |
=

Answer 36

1

Answer 37

yeah,

and what about

C. f(x) = x - 3
f(2) = 2 - 3
=

Answer 38

so c is correct

Answer 39

what did you get for 2 - 3

Answer 40

-1

Answer 41

so it has to Be D

Answer 42

is 1 the same as -1 ?

Answer 43

no

Answer 44

so now lets check D.

f(x)=│x-3│

D. f(x)=x-3 if x>3


what is f(4) ?

Answer 45

4

Answer 46

4-3=1

Answer 47

│4-3│=1

Answer 48

that fits with

f(x)=│x-3│

and with

D. f(x)=x-3 if x>3

what about f(23)?

Answer 49

│23-3│=20

Answer 50

and
D. f(x) = 23-3 (23>3)
= 20 also

Answer 51

so its D

Answer 52

yep
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Answer 53

can u help me with1 more

Answer 54

i think i have to go to bed, soory

Answer 55

it wont take long plx i just beed anwser

Answer 56

go on then

Answer 57

let f(x)= -2x x<0
0 x>0
which is equivalent
A.f(x)=x+│x│
B.f(x)=│x│-x
C.f(x)=2x
D.f(x)=2│x│

Answer 58

test some numbers for x

Answer 59

what do u think the anwser is

Answer 60

what if x=1 ? (1>0)

is A. correct?

Answer 61

yea

Answer 62

wait no

Answer 63

can you show some working

Answer 64

i only have 5 min to finish and this is the last question

Answer 65

im not going to tell you the answer, but i can check your working

Answer 66

ok

Answer 67

i got B is that corect

Answer 68

where is the working?