unit 6. for x 0 and 0 a 1, y = log a x if and only if x = a y. the function given by f (x) = log...
TRANSCRIPT
![Page 1: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/1.jpg)
NATURAL LOGSUnit 6
![Page 2: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/2.jpg)
For x 0 and 0 a 1, y = loga x if and only if x = a y.
The function given by f (x) = loga x is called the
logarithmic function with base a.
Every logarithmic equation has an equivalent exponential form: y = loga x is equivalent to x = a y
A logarithmic function is the inverse function of an exponential function.
Exponential function: y = ax
Logarithmic function: y = logax is equivalent to x = ay
A logarithm is an exponent!
![Page 3: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/3.jpg)
The function defined by f(x) = loge x = ln x
is called the natural logarithm function.
y = ln x
(x 0, e 2.718281)
y
x5
–5
y = ln x is equivalent to e y = x
In Calculus, we work almost exclusively with natural logarithms!
![Page 4: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/4.jpg)
01ln
1ln e
![Page 5: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/5.jpg)
EXAMPLES
32ln yx 32 lnln yx yx ln3ln2
2
3
lny
x 22
3
lnln yx yx ln2ln2
3
![Page 6: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/6.jpg)
EXAMPLES
5
432ln
z
yx
xy ln4ln
yx ln3ln22
1
zyx ln5ln4ln32ln
4ln
x
y
32ln yx
![Page 7: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/7.jpg)
Derivative of Logarithmic Functions
The derivative is
'( )(ln ( ) )
(.
)
d f xf x
dx f x
2Find the derivative of ( ) ln 1 .f x x x
2
22
2
( 1)(ln 1)
12 1
1
dx xd dxx x
dx x xx
x x
Example:
Solution:
Notice that the derivative of expressions such as ln|f(x)| has no logarithm in the answer.
![Page 8: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/8.jpg)
![Page 9: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/9.jpg)
EXAMPLE
3ln xy xln3
xxy
313'
![Page 10: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/10.jpg)
EXAMPLE
3ln 2 xy 32 xu
xdu 2
3
2'
2
x
xy
![Page 11: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/11.jpg)
EXAMPLE
xxy ln
Product Rule
1ln1
' xx
xy
xy ln1'
![Page 12: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/12.jpg)
EXAMPLE
2
3
1ln xy x1ln2
3
xxy
22
3
1
1
2
3'
![Page 13: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/13.jpg)
EXAMPLE
1
1ln
x
xy 1ln1ln
2
1 xx
1
1
1
1
2
1'
xxy
1
2
2
1'
2xy
1
1'
2
xy
![Page 14: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/14.jpg)
EXAMPLE
xy secln
xx
xxy tan
sec
tansec'
![Page 15: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/15.jpg)
EXAMPLE
xxy tansecln
xx
xxxy
tansec
sectansec'
2
x
xx
xxxy sec
tansec
sectansec'
![Page 16: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/16.jpg)
INTEGRATING IS GOING BACKWARDS
Finding the anti-derivative using natural logs is fun, fun, fun
![Page 17: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/17.jpg)
![Page 18: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/18.jpg)
3
5
x
dx 3xu
dxdu
u
du5
Cu ln5
Cx 3ln5
![Page 19: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/19.jpg)
1
22x
xdx 12 xu
xdxdu 2
u
du
Cu ln
Cx 1ln 2
![Page 20: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/20.jpg)
x
dx
1
xu 1
dxx
du2
1
duu
u 12
uu ln2
Cxx 1ln212
dxdux 2
xu 1
dxduu )1(2
duu
112
![Page 21: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/21.jpg)
2
2sin23
cos4
d
sin23u
ddu cos2ddu cos42
1,2
uat
5,2
uat
5
1
2u
du
uln2
1ln5ln2
5ln2
![Page 22: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/22.jpg)
xdxtan
dxx
x
cos
sin
xu cos
xdxdu sin
u
du
CxCu coslnln
Cxxdx coslntan
![Page 23: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/23.jpg)
INTEGRALS OF 6 BASIC TRIG FUNCTIONS
Cuudu sinlncot
Cuuudu tanseclnsec
Cuuudu cotcsclncsc
Cuudu coslntan
Cuudu sincosCuudu cossin
![Page 24: Unit 6. For x 0 and 0 a 1, y = log a x if and only if x = a y. The function given by f (x) = log a x is called the logarithmic function with base](https://reader035.vdocument.in/reader035/viewer/2022062308/56649c635503460f9490fae7/html5/thumbnails/24.jpg)
6
0
2tan
xdxxu 2dxdu 2
3
0
tan2
1
udu
3
0cosln
2
1
u
0cosln
3cosln
2
1
1ln
2
1ln
2
1 2ln1ln
2
1 2ln
2
1