## GiggleSquid 3 years ago If f(x)=4x+7 and g(x)= sqrt(x-3), what is (fog)(4)

1. GiggleSquid

keep getting these square root ones wrong. medal to correct answer

2. lgbasallote

lol bribing?

3. GiggleSquid

well, just want people to double check there answer

4. lgbasallote

5. GiggleSquid

lemme do it

6. lgbasallote

tag me when you have an answer

7. GiggleSquid

$\sqrt{23-3}$ 4.4721 but thats not right.

8. GiggleSquid

@lgbasallote

9. lgbasallote

solve for g(4) first

10. lgbasallote

$(f o g)(4) \implies f(g(4))$

11. GiggleSquid

ahhh, so 11

12. lgbasallote

yup

13. GiggleSquid

here is one that introduces h @lgbasallote Let f(x)=(4x^3+20)^2 and g(x)=4x^3+20. Given that f(x)=(hog)x, find h(x)

14. GiggleSquid

15. lgbasallote

find (h o g) x first

16. vishweshshrimali5

sorry to interrupt but Prefer this link .. for understanding ; http://www.regentsprep.org/Regents/math/algtrig/ATP7/compositionfunctions.htm

17. vishweshshrimali5

see the examples. . you may continue @lgbasallote

18. GiggleSquid

this may help, in helping me

19. GiggleSquid

wait, how do i find (hog)?

20. lgbasallote

find g(x) first

21. lgbasallote

what is g(x)

22. GiggleSquid

what do i use for x?

23. lgbasallote

x

24. GiggleSquid

isnt it just 4x^3+20 then?

25. lgbasallote

yup

26. lgbasallote

so therefore h(4x^3 + 20) = f(x) do you agree with this?

27. GiggleSquid

yes

28. GiggleSquid

where do i use that?

29. lgbasallote

hmm this was easier in my head...

30. GiggleSquid

lol

31. lgbasallote

how will you turn h(4x^3 + 20) into h(x) what do you think?

32. GiggleSquid

geeze, I have no clue.

33. lgbasallote

me neither :/

34. lgbasallote

try posting it as a new question maybe someone has an idea