## surryyy one year ago Determine the domain of the function f(x) = 2x - 4 when the range is {0, 12, 20}. {2, 8, 12} {0, 12, 20} {4, 16, 24} none of these

1. Nnesha

domain= x values range = y values

2. Nnesha

so substitute y for given set {0,12,20)one by one to find domain

3. Nnesha

how ?

4. anonymous

you need to solve for them and not guess

5. Nnesha

f(x) is same as y so $\huge\rm y=2x-4$ start with first number 0 substitute x for 0 what do you get ?

6. Nnesha

$$\color{blue}{\text{Originally Posted by}}$$ @Nnesha f(x) is same as y so $\huge\rm y=2x-4$ start with first number 0 substitute x for 0 what do you get ? $$\color{blue}{\text{End of Quote}}$$ i meant substitute y**8

7. anonymous

no no no you do not substitute x for 0 you substitute f(x) to each the values in the range. you said it yourself y = f(x) range = y domain = x so, $$f(x) = 2x - 4$$ means solve for x for each of the following: $$0 = 2x-4$$ $$12 = 2x-4$$ $$20 = 2x-4$$

8. anonymous

if you do not know how to solve for x, then you have no business taking the course.

9. Nnesha

$$\color{blue}{\text{Originally Posted by}}$$ @Nnesha $$\color{blue}{\text{Originally Posted by}}$$ @Nnesha f(x) is same as y so $\huge\rm y=2x-4$ start with first number 0 substitute x for 0 what do you get ? $$\color{blue}{\text{End of Quote}}$$ i meant substitute y** $$\color{blue}{\text{End of Quote}}$$ ^^^^^

10. surryyy

x = 2 x=8 x=12

11. anonymous

how did you GET those values? CAN YOU SHOW YOUR SOLUTION FOR EACH?

12. surryyy

0=2x−4 2x−4+4=0+4 2x=4 2x/2 = 4/2 x=2

13. surryyy

12=2x-4 2x−4+4=12+4 2x=16 2x/2 = 16/2 x=8

14. surryyy

20=2x-4 2x−4+4=20+4 2x=24 2x/2 = 24/2 x=12

15. surryyy

happy? fgt.

16. Nnesha

PERFECT! great job!! :=)

17. Nnesha

fgt????

18. surryyy

ty Nnesha.

19. Nnesha

yw