Question

Given the piecewise function shown below, select all of the statements that are true.
(will attach function in a sec!)

a. f(2) = 4

b. f(4) = 0

c. f(3) = 9

d. f(1) = -3
***Choose all that apply!! I don't get this at all!! Please help!! :) Thanks!

Answer 1

ok when x=2
which one of the 3 equations will you use?

Answer 2

IDK!! :O

Answer 3

f(2) means when x=2
f(0) means when x=0

Answer 4

Hi @dpaInc thanks for coming :)

Answer 5

@completeidiot thanks for helping too :)

Answer 6

hello....:) np...

Answer 7

i am still confused :O

Answer 8

oh wait so would it be answers B and D???

Answer 9

once you know the x value, you look at the range for each function
f(x) = -3x only when x is less than 0
f(x)=4 only when x is equal to 0
f(x)=x^2 only when x is greater than 0

Answer 10

looks that way

Answer 11

because B f(4)=0 corresponds with 4, x=0 and D f(1)=-3 corresponds with -3x, x<0 ???

Answer 12

So the final answer is B and D??? And A and C definitely do not apply? :)

Answer 13

for B,x=4 so y is equal to 4 but 4 is not equal to 0 so that has to be false
for D,x=1 so we use the last equation y=x^2, so y=1 but 1 is not equal to -3 so that is false as well

Answer 14

think of f(x) =y

Answer 15

wait what? so the answers are NOT B and D???

Answer 16

the number inside the parenthesis is equal to x

Answer 17

the answers are not B and D

Answer 18

So the answers are A and C???

Answer 19

in fear that you might not understand, please explain why those are the answers, if they are

Answer 20

and can u pls explain how?? cuz i am SUPER confused... sorry!!!

Answer 21

@completeidiot .... you're doing great... keep it up...:)
@iheartfood .... try to see what he ^^ is trying to say....

Answer 22

@dpaInc i reread everything @completeidiot wrote above but i am still extremely confused... :(

Answer 23

again
lets consider the number within the parenthesis is equal to x
and lets consider the answer when you substitute x into the equation as y
so f(x)=y


y= -3x only when x is less than 0
y=4 only when x is equal to 0
y=x^2 only when x is greater than 0

so as an example
f(-2) =?

x= -2, so we look for the condition it fits under.
-2 is less than 0 so we use the first equation
so we substitute that value into the first equation to get
6
therefore
f(-2)=6

Answer 24

okay lemme see... and try this in the problem to understand...

Answer 25

oh and do i plug it in to the equation that would make it true yes? or does it have to be true for all 3 equations??

Answer 26

no you're trying to determine which one is true
basically
solve
f(2)=??
f(4)=??
f(3)=??
f(1)=??

you compare those to the answers that were given, which ever matches means it is correct

Answer 27

so f(2)=4 goes under -3x=-12?

Answer 28

oops! f(2)=-6 right?

Answer 29

2 is not less than 0
so you would not use the first equation
2 is not equal to 0
so you would not use the 2nd equation

2 is greater than 0 so you would use the 3rd equation

Answer 30

oops! f(2)=4?

Answer 31

f(4)=0?

Answer 32

f(3)=9?

Answer 33

f(1)=1?

Answer 34

dont look at your answers
pretend they're all wrong
f(4)= ??

Answer 35

x=4
which is greater than 0
so which equation will you use?

Answer 36

OH i just plugged them in and that's what i got.... and only f(1) did not =-3..

Answer 37

and i would use equation 3 for f(4) right?

Answer 38

f(1) did not equal -3 so that means its wrong
and yes you would use equation 3 for f(4)

Answer 39

so D is now crossed out and not an answer yes? and f(2)=4, which matches so A is an answer?

Answer 40

yes and yes
what about B and C?

Answer 41

For B f(4) menas i use equation 3 also right?

Answer 42

yes because x=4 and 4 is greater than 0

Answer 43

so f(4)=16, which is not true so B is not an answer???

Answer 44

very good

Answer 45

and for the last one C, f(3) we use equation 3 also right?

Answer 46

good job guys...:)

Answer 47

why would you use the 3rd equation?

Answer 48

because 3>0 right??

Answer 49

good job
so f(3)=?

Answer 50

so f(3)=9 which is true so C is an answer also??

Answer 51

yup
before you go
2 more questions to see if you understand it

f(0)=??
and
f(-1)=??

Answer 52

f(0) uses equation 2 so the answer is 4?
and f(-1) uses equation 1, so the answer is 3??
So the final answers for my question are A and C then?
And did i get the practice questions right? :)

Answer 53

yes yes yes and yes
good job

what the graph would look like
there's an open circle at (0,0) to show that the lines reach it but is not equal to