Question

A logarithmic function is the inverse of an exponential function. Can someone explain this to me?

Answer 1

@Nnesha

Answer 2

@bibby

Answer 3

(1) p = ln q
(2) e^p = e^(ln(q)) = q
(3) [AND: just (1) in reverse] ln q = p

see this:
http://www.mathsisfun.com/sets/function-inverse.html

Answer 4

y=e^x->x=e^y

solve for y

Answer 5

I forgot how to do that... o.o

Answer 6

the log of a number is the power to which the base must be raised to get that number

Answer 7

to cancel out "e "you have to take ln both side
for example \[\large\rm ln e^x = x\]
\[\ln 1 =0\]
\[\ln e^7 =7\]

Answer 8

what's ln?

Answer 9

natural logarithm ;)

Answer 10

same rules for ln and log

Answer 11

so what's that? is it different from just log?

Answer 12

@bibby

\[y = e ^ {x} => x = e ^{y} => y = e ^ {e ^{ y}} \]

Answer 13

Okay. This is confusing me

Answer 14

nope same properties for ln
but you have to use ln when you are dealing with "e"
otherwise \[\rm ln x + \ln y= \ln(x \times y)~~~~ logx + \log y = \log (x \times y)\]

Answer 15

why?

Answer 16

why what ??
why ln cancel out e ??

Answer 17

why do you have to use ln with e?