Domain, Range, etc. help

[marshall1432]

Here are 5 problems I requested from my teacher for added practice and I wanted to try to solve them through here before I turned them in:

1. What is the range of the function f(x)=x^2?

2. For the following functions, find the value of f(5):
|x+2| if -4<x<1
4 if 1<x<3
-x+5 if x>3

3. Find the value of f(2) in the same functions given above^.

4. Determine the domain of the function:
2x^2-1 if 2<x<5
4-3x if 5<x<7

I will now post how I think it should be done and please take into account I'm not great at math:

1. {x|x not equal 0}
2. Unsure
3. Unsure
4. |x-2|<5

Can anyone help me please!!! thanks!

 

[skeeter]

Here are 5 problems I requested from my teacher for added practice and I wanted to try to solve them through here before I turned them in:

1. What is the range of the function f(x)=x^2?

range is f(x) > 0

2. For the following functions, find the value of f(5):
|x+2| if -4<x<1 5 is not in the domain
4 if 1<x<3 ditto
-x+5 if x>3 f(5) = -5 + 5 = 0

3. Find the value of f(2) in the same functions given above^.

try this again

4. Determine the domain of the function:
2x^2-1 if 2<x<5
4-3x if 5<x<7
the domain is given to you!

I will now post how I think it should be done and please take into account I'm not great at math:

1. {x|x not equal 0}
2. Unsure
3. Unsure
4. |x-2|<5

Can anyone help me please!!! thanks!

 

[marshall1432]

Okay, see, I told you im not good at math, sorry

1. f(x)>0

On #2 do you sub in 5 for x and solve it that way? and the same for #3?
#4 how did you figure out the domain? sorry to ask so many questions, i am just trying to figure this set out and how to work the problems correctly.

 

[skeeter]

do you even understand what domain means?

 

[marshall1432]

do you even understand what domain means?

Yeah, the domain is the set of all possible input values (usually x), which allows the function formula to work.