anonymous one year ago given that (5,4) is on the graph of f(x) find the corresponding point for the function f(-1/3x)

1. anonymous

$f \left(-\frac{ 1 }{ 3 } x\right)$

2. anonymous

3. zepdrix

If (5,4) is on the graph... then the function f(x) evaluated at x=5, will give us an output of 4.

4. zepdrix

Meaning, f(5)=4

5. zepdrix

Hmmm what can we do with that :d Sec, trying to understand the question.

6. zepdrix

@campbell_st @peachpi

7. anonymous

F(-1/3x) The -1/3 will multiply our x values by -3.. Does that make sense?

8. anonymous

I think so, you multiply 5 and 4 by -3?

9. anonymous

so to get (5.4) in this new equation you'd need.. F(-1/3x) x=-15 No your y does not change only how fast or slow it takes for the graph to reach that point

10. anonymous

if it was 3f(-1/3x) then we would multiply our "y" 3 times and our x by -3

11. anonymous

okay now I'm confused

12. zepdrix

oh is that what they wanted? Hmm wording was really confusing :U

13. anonymous

All I know is I'm supposed to enter an ordered pair and x is supposed to stay the same

14. anonymous

Suppose, F(x) = 3x F(5) = 3(5) F(5)= 15 (5,15)

15. anonymous

Now we have F(-1/3x) what would be the corresponding point for the function

16. anonymous

I'm not sure

17. anonymous

so we know when x=5 then we have 15

18. anonymous

f(-1/3x) = F(5) -1/3x =5 x=-15

19. anonymous

so that's it?

20. anonymous

so on our second equation we know if x is -15 we have f(5) = y

21. anonymous

F(-1/3*-15) F(5) =4

22. anonymous

makes sense?

23. anonymous

its just your x changing not y

24. anonymous

okay so 5 stays the same, what happens to y?

25. anonymous

So we have a point (5,4)

26. anonymous

5,4 is the original points given, I didn't even think it was possible that the answer would literally be in the question

27. anonymous

this can be rewritten as f(5)= 4 F(x) we have this new equation which is the same general shape but it has f(-1/3)

28. anonymous

F(-1/3x)

29. anonymous

(|dw:1436663494341:dw|

30. anonymous