## 0214 3 years ago If f(x) = x − 4 and g(x) = 1 over 2x − 2, find f[g(−6)].

1. bahrom7893

g(-6) = 1/(2*(-6)-2) = 1/(-12-2) = -1/14

2. bahrom7893

f [g(-6)] = f [ -1/14] = (-1/14) - 4

3. 0214

-4 isnt an option.

4. 0214

9 3 −9 −3

5. bahrom7893

Well did I say 4 is the answer? whatever -1/14 - 4 is.. wait

6. bahrom7893

By the way is it: |dw:1352646754665:dw|

7. 0214

first one

8. bahrom7893

oh, then scratch what i did before, and use parenthesis when you post the question

9. bahrom7893

f(g(-6)) = 1/[2*(-6)] - 2 = (-1/12) - 2 = (-1/12) + (-24/12) = -25/12

10. bahrom7893

wait that's just g(-6)

11. bahrom7893

now: f(g(-6)) = f(-25/12) = -25/12 - 4 = (-25 - 48)/12 = -73/12... i don't see where i'm going wrong.

12. bahrom7893

@UnkleRhaukus can u go over this real quick?

13. UnkleRhaukus

all of it?

14. bahrom7893

lol i guess u can just solve the question, i don't see what i did wrong, because i am not getting any of his options

15. 0214

i sent them to you

16. 0214

9 3 −9 −3

17. bahrom7893

like i said, im not getting any of the options......

18. UnkleRhaukus

$g(x)=\frac1{2x}−2$ $g(−6)=\frac1{2(-6)}−2=-\frac{1}{12}-2=\frac{-36}{12}=\color\gray{-3}$

19. bahrom7893

unkle.... are you sure you added those right?

20. UnkleRhaukus

hmm, no

21. UnkleRhaukus

$g(−6)=\frac1{2(-6)}−2=-\frac{1}{12}-\frac{24}{12}=\frac{-25}{12}$

22. UnkleRhaukus

$f(-25/12)=-\frac{25}{12}-4=-\frac{25}{12}-\frac{48}{12}=-\frac{25+48}{12}\color\grey=\color{white}{\frac{-73}{12}}$

23. UnkleRhaukus

im getting what you are getting now bahrom

24. 0214

how about this one If f(x) = −2x − 4 and g(x) = x + 4, find (f over g)(−8).

25. 0214

options are −3 3 −1 1

26. UnkleRhaukus

what do you mean by 'over'

27. UnkleRhaukus

do you mean $$f\circ g$$

28. 0214

f/g

29. UnkleRhaukus

f(x) = −2x − 4 g(x) = x + 4 (f / g)(x) = ( −2x − 4 ) / ( x + 4) (f / g)(−8) = ( −2(-8) − 4 ) / ( (-8) + 4)

30. 0214

31. 0214

??

32. UnkleRhaukus

( −2(-8) − 4 ) / ( (-8) + 4) =( 16 − 4 ) / ( -4) =