Question

question inside :)

Answer 1

quetsion!! :)

Answer 2

answer choices A,B,C,D from top to bottom :)

idk how to do this.. please explain? :) thanks!

Answer 3

hi!! do u get this problem? :)

Answer 4

i like it more when there are presents inside

Answer 5

lol :P

Answer 6

Do you know how to find the domain of a function??

Answer 7

not really :(

Answer 8

You cannot proceed to the answer for this question if you do not know that...

Answer 9

ohhh can u pls explain to me then?? i always get confused and mixed up how to find them :(

Answer 10

f(x) represents that there is function f which depends upon value of x..

That is why we write it as f(x) pronounced as f of x..

See, domain is the value of x for which the function is defined..

But value of f(x) comes to be indefinite or infinity then function f(x) is not defined...

Answer 11

okay hold on lemme process that lol :P

Answer 12

See, the concept below:

Suppose I have a function as : f(x) = 2x + 3


Here you can plug in values for x as 1 2 3 4 5 -1 -2 etc etc..

But when you plug in one value of x the f(x) comes out to be different then when you put other value of x..
Getting this??

Answer 13

okay i think i get it... kinda following :)

Answer 14

See: I put x = 1 : f(x) = 2x + 3 this will becomes : f(1) = 2(1) + 3 = 5

Now put x = 2 f(x) = 2x + 3 this will become : f(2) = 2(2) + 3 = 7

Are they different??

Yes they are..

Getting???

Here value of f(x) is depending upon value of x..

Right??

Answer 15

okay yes i see now :) so what do i do to find the answer to my problem? how do i use that?

Answer 16

This is only the basic concept I am building in you so that you can get the concept first..

Answer 17

okay =)

Answer 18

Now can you tell me one thing :

f(x) = 2x+3

Here can you give x a value which can make f(x) undetermined ??

undetermined is the value that cannot be defined..

Can you tell??

Answer 19

a value that cannot be defined.. is that considered 0? like when it = 0?

Answer 20

See. for x = 0, f(x) = 2x + 3 is : f(0) = 0 + 3 = 3

3 is a determined or known value..

You have to find an undetermined value for f(x)..

Also, if you got f(x) = 0 for any value of x then also 0 is the defined value..

Answer 21

so undetermined would be defined as what? I'm confused on that part.. i get what the defined or determined values are but idk undetermined

Answer 22

See: In this case : f(x) = 2x+3, you will not get any undetermined value for f(x) as for all value of x you will get f(x) as having a known value..

Answer 23

Don't be upset dear..

See I give you one more example : f(x) = 1/x


Can you tell here in the denominator can x be 0 ??

Answer 24

no

at least i don't think it can..

Answer 25

Yes, this is what the domain of this function..

For :
\[f(x) = \frac{1}{x}\]
\[x \ne 0\]

Answer 26

okay i see.. so what about my problem tho?

Answer 27

Here fo x = 0 you will get f(x) as undetermined...

Answer 28

are we doing my problem now?

Answer 29

Yes I know come to your problem..

Answer 30

okay :)

Answer 31

Now tell me the value in the square root bracket is determined or undetermined???

Answer 32

For example:

\[\sqrt{-1}\]

do you know the value for this??

Answer 33

which sq.rt bracket?? I'm getting confused... r u talking bout my problem now?

Answer 34

=i
?

Answer 35

Yes I am talking of your problem now..

Answer 36

Don't use complex number concept here..

Answer 37

See can you tell me the value of following :

\[\sqrt{-6}\]

Answer 38

You can solve this :

\[\sqrt{4} = 2\]

but cannot :

\[\sqrt{-4} = undetermined\]

Answer 39

Getting or not??

Answer 40

yes :)

Answer 41

Yep..

Now remember this : Value in any Square root bracket must not be negative..

Okay??

Answer 42

okay :) how do i find the answer to my problem tho?

Answer 43

You have to just use analyze the answer what it can be..

Answer 44

idk how to tho :( can u pls show me it? i understand better when its all layer out in front of me.. i understand the concept now, but idk how to solve... can u pls show me? :)

Answer 45

Let us try last option first so that you can get the idea how to find domain..

Last one is:

\[f(x) = \sqrt{x+a} + b\]

Let f(x) = y

So:

\[y = \sqrt{x+a} + b\]
Now to find domain:

we know that value inside the brackets must not be negative..
So,

value inside the square root must be positive:

So: \(x+a \ge 0\)

Answer 46

i think i understand how to find the domain :) i just don't get how to solve my problem cuz of the infinity signs and stuff.

Answer 47

Here on solving : \(x \ge -a\)

Or in notation : \([-a,0)\)

Answer 48

Hey man, \([a, \infty\)) just show that x will take value between a and infinity..

Answer 49

kk can u pls show me it all in one post? i understand better in one thing, opposed to scattered... can u pls do that? :)

Answer 50

Now In last one we got [-a, infinity) but we need : [a, infinity)..

Answer 51

Now : let us try for second one..

Can you try the second choice it is just same as last one..

Try atleast once..

Answer 52

is this my problem? I'm confused

Answer 53

ohhh so second one is f(x)=sq.rt. x-a +b

Answer 54

See, we have to try all the four..

By practice, you will get the concept of domain and range. and you can them simply tell by only seeing with your eyes..

Yes find the domain for that just same as I did above..

Answer 55

so i get