# Homework Help: Domain and range help

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1. Aug 2, 2016

### Mark53

1. The problem statement, all variables and given/known data
Suppose f is a function with domain [-2,10] and range [5,10]. Find the domain and range of the following functions.
(a) f(2x+4)

(b) 2f(x)+4

3. The attempt at a solution

Would I just substitute the in the domain and range values to find the answer?

2. Aug 2, 2016

### BvU

Don't ask. Do it: that counts as an attempt at solution. Ask when stuck...
Or (in a friendlier manner ) what do you get when you do as you propose ?

3. Aug 2, 2016

### Mark53

[-2,10] if i sub this values into f(2x+4) i would get 0 and 24 does this mean that the domain would be (0,24)

Would I just do the same for the range?

4. Aug 2, 2016

### Staff: Mentor

Do you know what is meant by domain and range? Can you define it?
Hint: Is f(24) defined?

5. Aug 2, 2016

### Mark53

the domain is pairs of x coordinates in order and the range is pairs of y coordinates in order

6. Aug 2, 2016

### jbriggs444

The domain of a function is the set of values which are allowed to be used as inputs to the function. The notation "[-2,10]" denotes a range of values from -2 up through 10, inclusive. It does not denote an ordered pair.

7. Aug 2, 2016

### Ssnow

Remember that $f(2x+4)=f\circ g$ where $g(x)=2x+4$, the composition requires that the range of $g$ is included in the domain of $f$ ...