Math 12AP – Exponents and Logarithms Review

 

The Equations!

 

General Form

Transformational Form

a = initial value of the function

 (... the y-intercept of the graph)

b = the common ratio

  • if b > 1 then growth curve
  • if 0 < b < 1 then decay curve

c = time to change by the common ratio

d = the horizontal asymptote

VS = vertical stretch                               

VT = vertical translation

b = common ratio

HS = horizontal stretch.  If HS < 0, then the graph will change from growth to decay (or decay to growth if 0 < b < 1)            

HT = horizontal translation        

 

 

The Shape of an Exponential Function - The terms of arithmetic sequence form a linear function.  The graph of this linear function will be a straight line.  The terms of a geometric sequence form an exponential function.  The graph of an exponential function will be a curved line that gets steeper and steeper.

 

Exponential Growth (e.g. ).  The first graph, , shows exponential growth.  Exponential growth can be used to model functions like nuclear reactions, population growth, and investment growth. 

           

 

Exponential Decay (e.g. ).  The second graph, , shows exponential decay.  Exponential decay can be used to model functions like carbon-14 dating and depreciation of car values.

 

Exponent Rules

 

 

 

Logarithms - A logarithm is the inverse operation of an exponent.  That means that whatever an exponent does, a logarithm with “undo.”  The argument of a logarithm can never be a negative number.

 

Logarithms Rules