## anonymous 5 years ago Inverse of Log base 4 of x

1. anonymous

y=4^x\[f(x)=4^x\] ?

2. anonymous

Yes Perto! xD

3. anonymous

*gasp i was thinking that! well there's one i got right on the test..

4. anonymous

Now, try this one! Log base 2 of x + 3

5. anonymous

the inverse of that?

6. anonymous

yesh!

7. anonymous

f(x)= 2^(x+3)

8. anonymous

?

9. anonymous

Nope!

10. anonymous

D:

11. anonymous

f(x)= 2^x ?

12. anonymous

wait a sec!

13. anonymous

wait lemme see!

14. anonymous

where's hanh?

15. anonymous

The answer is y = 2^x - 3

16. anonymous

why minus?

17. anonymous

can you show me how you did that

18. anonymous

cuz its the inverse

19. anonymous

darn..that means i probably got that wrong in the test. :\

20. anonymous

Okie! So it's: y = Log base e of x + 3, NOT (x+3) So it's 2^y = x + 3 There fore, 2^x - 3 = y

21. anonymous

id remember if i got that right

22. anonymous

base 2*

23. anonymous

next problem

24. anonymous

Log base x of 3x

25. anonymous

thats wierd

26. anonymous

x ^ y = 3x Inverse = x^x = 3y, so it's y = (x^x) / 3

27. anonymous

thats wierd

28. anonymous

okay, I'll change base x to base 2

29. anonymous

why?

30. anonymous

so that you won't be confuse with which x to switch

31. anonymous

2^y or x^y in the original = 3x Inverse = 2^x original x^x = 3y so divide both side by 3 to get y y = (2^x)/3 or (x^x)/3 in the original