Question

Domain question? f(x)=4/x^2

Answer 1

I have choices. Hang on. >:P

Answer 2

What number can you not sub in as x?

Answer 3

What number will give you a undefined value for f(x)

Answer 4

I guess zero isn't an option.

Choices:
A) x ≥ 0
B) All real numbers except 0
C) All real numbers except 3
D) All real numbers

Answer 5

Any guesses at all?

Answer 6

It's B, right?

Answer 7

Yup

Answer 8

f(x) = (x - 2)^2 + 2 What about this one? It's range instead of domain... I just can't seem to get range or domain. :c @Australopithecus

Answer 9

Yay! C:

Answer 10

Domains are simple,

Just remember the following math rules


-You cannot take the logarithm of a number equal to or less than zero,
For example:
log(-1) =/= undefined

(if you are curious as to why this is just remember log(x) = y is the same as 10^y = x try to make x negative in this form, you cant.


-You cannot divide by zero so,
For example
0/0 = undefined
1/0 = undefined
0/1 = 0

-You cannot take the square root of a negative number, you can take the square root of zero

For example,

(-2)^(1/2) = an imaginary number
(-3)^(1/6) = an imaginary number
(0)^(1/66) = 0


Another hint always check the exponent on the variable x, if it is even remember all numbers subbed into it will give you a positive, for example,

(-2)^2 = 4
(-2)^3 = -8
(-2)^4 = 16

Im pretty sure this covers domains

Answer 11

Oh, gosh. Thanks. C: Is it pretty much the same thing for range?

Answer 12

Well not really, for the range I normally check the extreme values of x in the domain, or I graph the function, or if it is a polynomial you can find its vertex (Look up guides on youtube)

Answer 13

Awesome. Thanks. c: God bless you!