If f(x) = log3 (x + 1), what is f^−1(2)?

Question

hartnn · Answer

can you find f^(-1) (x) first ?

hartnn · Answer

y=log_3 (x+1)

isolate x from here

anonymous · Answer

so would it be log3*1 = x

hartnn · Answer

what ? 

do u know $if, \log_ab=c  \implies a^c=b  $
?

anonymous · Answer

no

hartnn · Answer

now you know,
so from that what about 
$\log_3(x+1)=y  \implies ???$

anonymous · Answer

c^y = ( x + 1 ) .... i just took the formula you gave me and plugged in

hartnn · Answer

you mean $\huge 3^y=x+1$
instead of c ?

anonymous · Answer

oh ok

hartnn · Answer

and f^(-1) (2) means the value of y is given to be 2

so you just need 'x' from 
$\huge 3^2=x+1$
got this ? any doubts till here ?

anonymous · Answer

1

8

10

27 

these are my answer choices

hartnn · Answer

what is 3^2 =... ?

anonymous · Answer

9

hartnn · Answer

yes,
so can u find x from 
9=x+1 ??

anonymous · Answer

x=8

hartnn · Answer

correct! :)

anonymous · Answer

Given the function f(x) = 0.3(4)^x, what is the value of f^−1(6)? 
will i do the same for this

hartnn · Answer

6 = 0.3 4^x
yes! same :)

anonymous · Answer

do i multiply 0.3 and 4

hartnn · Answer

nopes, 
6/0.3 = 4^x

anonymous · Answer

i keep getting 1.03

hartnn · Answer

what are the choices ?

anonymous · Answer

0.360

1.242

2.161

2.312

hartnn · Answer

with 4^x = 6/0.3
using a calculator, i get 
2.161

anonymous · Answer

what do i put in first

hartnn · Answer

put where ?

anonymous · Answer

the answer was correct thank you

anonymous · Answer

& i have the TI 84plus calculator ..i'm still trying to work it lol

hartnn · Answer

its ok :)
and welcome ^_^

anonymous · Answer

would you like t help me on another assignment

hartnn · Answer

ask your questions in a new post,
so that even if i am unavailable, others can help you :)

anonymous · Answer

it's up