derive exponential derivative rule
DESCRIPTION
This briefly goes through a numerical derivation of the derivative rule for exponential functions.TRANSCRIPT
![Page 1: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/1.jpg)
The Derivatives of Exponential Functions
Calculate the derivative of f(x)=2x
0 0 0
0
2 2 2 2 2 2 (2 1)'( ) lim lim lim
2 1'( ) 2 lim
x h x x h x x h
h h h
hx
h
f xh h h
f xh
![Page 2: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/2.jpg)
The Derivatives of Exponential Functions
Calculate the derivative of f(x)=2x
0 0 0
0
2 2 2 2 2 2 (2 1)'( ) lim lim lim
2 1'( ) 2 lim
x h x x h x x h
h h h
hx
h
f xh h h
f xh
What is this????
![Page 3: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/3.jpg)
The Derivatives of Exponential Functions
Fill out the following table for values of h close to zero.
h-0.01
-0.001-0.00010.00010.0010.01
0
2 1lim
h
h h
![Page 4: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/4.jpg)
The Derivatives of Exponential Functions
Fill out the following table for values of h close to zero.
h-0.01 .69075
-0.001 .69291-0.0001 .693120.0001 .693170.001 .693390.01 .69556
0
2 1lim
h
h h
![Page 5: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/5.jpg)
The Derivatives of Exponential Functions
Fill out the following table for values of h close to zero.
h-0.01 .69075
-0.001 .69291-0.0001 .693120.0001 .693170.001 .693390.01 .69556
0
2 1lim
h
h h
This table suggests that the limit DOES
exist, and has a value of about 0.693
![Page 6: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/6.jpg)
The Derivatives of Exponential Functions
Fill out the following table for values of h close to zero.
h-0.01 .69075
-0.001 .69291-0.0001 .693120.0001 .693170.001 .693390.01 .69556
0
2 1lim
h
h h
This table suggests that the limit DOES
exist, and has a value of about 0.693
So we can write: 693.02)2( xx
dx
d
![Page 7: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/7.jpg)
So the derivative of 2x is proportional to 2x with a constant of proportionality 0.693.
Hmmmm…
693.02)2( xx
dx
d
![Page 8: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/8.jpg)
The Derivatives of Exponential Functions
Calculate the derivative of f(x)=ax
h
aaxf
h
aa
h
aaa
h
aaxf
h
h
x
hx
h
xhx
h
xhx
h
1lim)('
)1(limlimlim)('
0
000
![Page 9: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/9.jpg)
The Derivatives of Exponential Functions
Calculate the derivative of f(x)=ax
h
aaxf
h
aa
h
aaa
h
aaxf
h
h
x
hx
h
xhx
h
xhx
h
1lim)('
)1(limlimlim)('
0
000
What is this????
![Page 10: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/10.jpg)
Here is for different values of a0
1lim
h
h
a
h
a
2 0.693
3 1.0986
4 1.386
5 1.609
6 1.797
7 1.946
0
1lim
h
h
a
h
( )xda
dx
693.02)2( xx
dx
d
![Page 11: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/11.jpg)
Here is for different values of a0
1lim
h
h
a
h
a
2 0.693
3 1.0986
4 1.386
5 1.609
6 1.797
7 1.946
0
1lim
h
h
a
h
Use your calculator to plot these points.
What type of function does it look
like?
( )xda
dx
693.02)2( xx
dx
d
![Page 12: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/12.jpg)
Here is for different values of a0
1lim
h
h
a
h
a
2 0.693
3 1.0986
4 1.386
5 1.609
6 1.797
7 1.946
0
1lim
h
h
a
h
Turns out that
the graph is just
y = ln(a)
( )xda
dx
693.02)2( xx
dx
d
![Page 13: Derive Exponential Derivative Rule](https://reader036.vdocuments.site/reader036/viewer/2022082804/5482f1a75906b5a3158b45e2/html5/thumbnails/13.jpg)
Here is for different values of a0
1lim
h
h
a
h
a
2 ln(2) = 0.693
3 ln(3) = 1.0986
4 ln(4) = 1.386
5 ln(5) = 1.609
6 ln(6) = 1.797
7 ln(7) = 1.946
0
1lim
h
h
a
h
( )xda
dx
)2ln(2)2( xx
dx
d
)3ln(3)3( xx
dx
d
)4ln(4)4( xx
dx
d
)5ln(5)5( xx
dx
d
)6ln(6)6( xx
dx
d
)7ln(7)7( xx
dx
d