{[ promptMessage ]}

Bookmark it

{[ promptMessage ]}

# 2-3 - 2-3 Logarithmic Functions The common log of a number...

This preview shows pages 1–4. Sign up to view the full content.

2-3 Logarithmic Functions The common log of a number is that exponent (or power) to which 10 must be raised to obtain the number. Notation :y = log (x) or y = log x "y = log of x" Example: log (1000) = . . . . . . the power to which 10 must be raised to obtain 1000 so log(1000) = 3 Another way to put it: 3 = log(1000) because 10 3 = 1000 y = log(x) means 10 y = x Be CAREFUL! log x + 2 log(x + 2) log x + 2 = log(x) + 2 Keep this in mind at all times: A LOG IS AN E XPONENT !!!! Practice: x 1 10 1000 .1 log x 2-3 p. 1

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
Since logs are defined using exponentials, any “log x” has an equivalent “exponent” form, and vice-versa. Going from log form to exponent form (a visual scheme) LOG FORM EXPONENT FORM Ex. log 5 13 = x 5 x = 13 Remember – a log is an exponent ___________________________________________ Going from exponent form to log form EXPONENT FORM LOG FORM Ex. y 14 = x ==> log y x = 14 Remember -- a log is an exponent 2-3 p. 2
Inverse properties of logarithms Think about log 10 x : log 10 x is the power to which we must raise 10 to get 10 x which is … x! so … log 10 x = x Think about … 10 log x : log x

This preview has intentionally blurred sections. Sign up to view the full version.

View Full Document
This is the end of the preview. Sign up to access the rest of the document.

{[ snackBarMessage ]}