4.3           Differentiation of Logarithmic and Exponential Functions

 

Graph:        y1 = ln x

                   y2 = nDeriv(y1,x,x)

 

Explore the graph of y2 which is the “numeric” derivative of ln(x)

         [image]

 

Derivative of ln x              for  x > 0

 

Examples

                                                                 

 

 

 

 

 

 

 

 

 

Consider the composite function

 

 


Chain Rule for Logarithmic Functions

If u(x) is differentiable function of x, then

         

 

Examples

                             

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Graph:        y1 = e ^ x

                   y2 = nDeriv(y1,x,x)

 

Explore the graph of y2 which is the “numeric” derivative of

 

 


Derivative of Exponential Function

         

 

Examples

                                           

 

 

 

 

 

 

 

 

 

Consider the composite function   

 

 

 

 

 

 

 

 

 

Chain Rule for Exponential Functions

                   If u(x) is a differentiable function of x, then

         

 

Examples

                                                   

 

 

 

 

 


                                                 

 

 

 

 

 

 

 

 

 

 

Find the largest and smallest value (absolute max and min) over the prescribed closed interval.

#40     

 

 

 

 

 

 

 

 

 

 

 

 

Application 

#74  COMPOUND INTEREST

Money is deposited in a bank offering interest at an annual rate of 6% compounded continuously.  Find the percentage rate of change of the balance with respect to time.

 

 

 

 

 

 


#80 ALCOHOL ABUSE CONTROL

Suppose the percentage of alcohol in the blood t hours after consumption is given by  .

a)     At what rate is the blood alcohol level changing at time t?

 

 

 

 

 

 

b)     How much time passes before the blood alcohol level begins to decrease?

 

 

 

 

 

 

 

 

 

 

 

c)     Suppose the legal limit for blood alcohol is 0.04%.  How much time must pass before the blood alcohol reaches this level?  At what rate is the blood alcohol level decreasing when it reaches the legal limit (the 2nd time)?

 

 

 

 

 

 

 

 

 

 

Assignment:  Page 335, 1-31 odd, 39, 45, 47, 51, 73