Unit 2 B Flashcards
log function general form
f(x)=alog(b)x
a does not = 0
b > 0
domain of general log function
(0, inf)
cannot take the log of a negative number
range of general log function
(-inf, +inf)
like a square root
if a > 0 and b >1
cd, growth
VA of reg log
x = 0
if a < 0 and b > 1
reflection over x axis
cu, decay
increasing vs. decreasing
only one!
no relative extrema unless on a closed interval
cu vs. cd
only one!
no points of inflection
end behavior limit statements of a log
left as x –> 0 (+/-)
right as x –> inf
logs in table
x values change proportionally
product property of logs
log(b)xy = log(b)x + log(b)y
quotient property of logs
log(b)x/y = log(b)x - log(b)y
power property of logs
log(b)x^m = m*log(b)x
to use power rules of logs…
bases (b) must be the same
b^log(b)c =
c
log(b)b^a =
a
change of base property of logs
log(b)a = log(c)a/log(c)b
natural logarithm function
lnx
lnx =
log(e)x
log graph
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product property of exponents
b^m*b^n=b^(m+n)
power property of exponents
(b^m)^n=b^m*n
negative exponent property
b^-n=1/b^n
if logs have the same base and are set equal to each other…
can cancel log