INTRODUCTION

What can the student do with this program?

  The user of this program can edit and plot three functions:
  F(x), G(x) and H(x) where H(x) is an expression using only F(x)
  and G(x).  Functions can be plotted in either rectangular or
  polar coordinates.  With rectangular coordinates, the function
  values are plotted as conventional y values.  With polar
  coordinates, the x variable is the same as conventional theta 
  and the function values are the radius, r.  Edited functions and
  plotting parameters can be saved to a file that is created and 
  named by the student.  These exercise files can also be saved, 
  loaded, renamed or deleted.










How does the student select and edit a function?  

  For F(x) or G(x), the user can select one of five function
  types: polynomial, factored polynomial, trig, exponential or
  logarithmic.  The constants in these expressions can be edited
  over a range of positive and negative values.  By setting some
  constants equal to zero and others equal to one, the functions
  can be simplified.  A simplified version of the function is
  written on the screen and updated as the user changes the
  various constants.  Among the five function types that can be
  edited, for convenience, two of them are called polynomial and 
  factored polynomial.  These functions can be other than true 
  polynomials since they may be given negative and fractional 
  exponents.
    





How does this program help the student to master pre-calculus
mathematics?  

  1)  The effects of negative, positive, odd, even and fractional
      exponents are readily observed as well as those of
      coefficients and additive constants.  
  2)  Discontinuities of various types are easily illustrated.
  3)  Odd and even symmetry can be demonstrated.  
  4)  The powerful effect of using functions of functions can be
      demonstrated to the student in creative and interesting
      ways.  
  5)  Intersections of functions which are often solutions to
      various types of conditional word problems involving
      simultaneous equations can be illustrated.
  6)  How a function looks when plotted in rectangular and then 
      polar coordinates can be quickly observed and compared.