## anonymous one year ago .

1. anonymous

their all negative options. I just didn't notice there weren't there sorry.

2. anonymous

replaced x with -4

3. anonymous

isn't it g(x)*f(x)*(-4)

4. anonymous

are you familiar with these?

5. anonymous

actually what i hav studied is that f(x) or g(x) can be written as f or g and f'g is f multiplied g

6. anonymous

I think there's a few ways you can actually do it.

7. anonymous

there is also braces for (f'g) separating it from (-4)

8. anonymous

@dan915 @amilapsn

9. anonymous

those ways can change the entire ans. actually!

10. anonymous

@nincompoop

11. anonymous

yeah

12. amilapsn

Here's the question is $$(g\circ f)(x)$$ right?

13. anonymous

yeah

14. amilapsn

Here's the thing: $(g\circ f)(x)=g\left( f(x)\right)\\ gf(x)=g(x)\times f(x)$ right?

15. amilapsn

that circle between g and f means g "of" f

16. Astrophysics

Still confused? It's the same as before g(f(4))

17. Astrophysics

Same sort of question

18. anonymous

I did g(f(-4)) = 3(4x+7)-5 but that's wrong

19. anonymous

so now I'm going through everything again

20. Astrophysics

That's g(f(x)), you're on the right track g(x) = 3x-5 and f(x) = 4x+7 g(f(x)) = 3(4x+7)-5 for g(f(1)) we plug in 1 now where the x is. g(f(1)) = 3[4(1)+7]-5

21. anonymous

oh I was doing -4 but I do 1 I guess.

22. Astrophysics

Oh oops it's -4

23. anonymous

oh

24. Astrophysics

g(f(-4)) = 3[4(-4)+7]-5

25. Astrophysics

You're doing it right then, why doubt yourself? :P

26. anonymous

The other people helping me were showing me different things so I just assumed I was wrong. I was feeling really confident about it actually. Anyways I was right and the answer is -32.

27. Astrophysics

Yay :)

28. anonymous

!!