## Katieann16 2 years ago Help me .

1. math>philosophy

lol

2. Katieann16

if \[f(x)=x ^{2} \] and \[g(x)=x+4\] find: A) ( fog ) (x) B) (fog) (2)

3. Katieann16

@math>philosophy shut up lol

4. math>philosophy

do you know how to evaluate composite functions

5. Katieann16

no

6. math>philosophy

take the function g(x) and put it into the variable for f(x) so f(x) = (x+4)^2 right

7. Katieann16

yeah .. lol

8. math>philosophy

so just plug in whatever you want to

9. Katieann16

@jim_thompson5910

10. Katieann16

No

11. math>philosophy

yes

12. Katieann16

NO

13. math>philosophy

yes

14. Katieann16

okay .

15. math>philosophy

good

16. Katieann16

Shut up

17. jim_thompson5910

f(x)=x^2 f(g(x))=(g(x))^2 f(g(x))=(x+4)^2 (f o g)(x)=(x+4)^2

18. jim_thompson5910

optionally, you can expand (x+4)^2 to get x^2 + 8x + 16, but again, it's optional in my view

19. jim_thompson5910

to find (fog) (2), you plug x = 2 into (f o g)(x)=(x+4)^2 to get (f o g)(x)=(x+4)^2 (f o g)(2)=(2+4)^2 I'll let you finish

20. Katieann16

(fog)(2)= (6)^2

21. jim_thompson5910

keep going

22. Katieann16

(fog)(2)= 12?

23. Katieann16

36*

24. jim_thompson5910

36, yes

25. Katieann16

26. jim_thompson5910

yep

27. Katieann16

Thank you(:

28. jim_thompson5910

yw