Question

state the domain and range f(x)=2(1/3)^x

Answer 1

domain all of real
range is positive R

Answer 2

howd you get that?

Answer 3

all the possible values of x which satisfies the relation will give you the domain..
n for every x the outcome gives you the range

Answer 4

Basically you're looking for disallowed values for x. If for example you had \(\sqrt{x}\) for your function you would know that negative numbers for x are not allowed. If you had \(\frac{4}{x}\) then 0 would not be allowed. If you had \(\sqrt{5-x}\) then your domain would be numbers less than or equal to 5. etc

Answer 5

shouldnt they be numbers?

Answer 6

The domain and range are sets of numbers. There are many values you can plug in for x and get many different values for the function.

Answer 7

so why is the domain and range not numbers?

Answer 8

it is a set of numbers

Answer 9

????

Answer 10

you dont understand what is meant by a "set of numbers"??

Answer 11

i just dont understand what your saying

Answer 12

{1, 2, 3.4, 15} is a set of 4 numbers.
(-5,1) is a set of infinitely many numbers between -5 and 1, but not including -5 or 1

Answer 13

i get that!!! I just dont understand the domain and range

Answer 14

Well the domain is just a set of numbers that are 'legal' to plug in for x.

Answer 15

If your function is well behaved (doesn't divide or take the square root) then anything is legal. Otherwise you might have to restrict what x can be. If you divide by x, then x cannot be 0. If you divide by x+3 then x cannot be -3. If you take the square root of x, then x cannot be negative, etc.

Answer 16

i dont get it

Answer 17

Can you take the square root of a negative number?

Answer 18

(and get a real result)

Answer 19

I have to go, but we can talk about it another time if you like.

Answer 20

margaret are you aware of complex numbers?

Answer 21

no im not of complex numbers