Entering Functions in Graphing Tools

Getting Started

• Access the quick function entry screen by pressing the button or clicking the right mouse button
• Type a function into the Functions box. Each line is a separate function.
• Press Enter
• Adding “y=” to the front of the function definition is optional for Cartesian functions (but not other types of functions or inequations)

Entering Functions

• Most occasions, you can type the equation as you see it and the graph tool will interpret it correctly
• There are a limited number of codes and keywords you need to learn to enter every possible function

Codes to Remember

• Use codes as follows:
  • =
  • >=
  • <
  • / (followed by a space)
  • pi
  • th
  • sqrt
  • 3root

Fractions

• Use / key for fractions
• Complex numerators or denominators must be surrounded with brackets

Spaces in Functions

• Spaces can determine the meaning of functions
  • sin2 x equals sin x^2
  • sin 2x equals sin(2x)

Polar Functions

• Enter polar functions using r and th (which will be shown as )
  • Example: r = 2sin2 3th

Inverse Functions

• Enter inverse functions by typing x in terms of y or theta in terms of r
  • Example: x = 12/y

Inequations

• Can be drawn for Cartesian, Inverse and Polar graphs.
• Replace the = with >=, or <
• Example: y >= 3x - 7

Parametric Functions

• Enter the x and y components in terms of t. Separate with a comma
  • Example: x = sin t; y = cos 3t
• Parametric functions are graphed with a default domain of 0  t  20 unless otherwise specified

Implicitly Defined Relations

• The graph tool can graph any function expressed in terms of x & y
• If the graph tool cannot rearrange the relation, it will graph the relation using a different technique that restricts the analysis that the graph tool can perform

Complex Numbers

• Enter complex numbers in terms of z and i OR cis
  • Example: z4 = 25 + 4i

Slope Fields

• Include y’ in your function
  • Example: y' = 3x + 2y

Plot as Points

• Plot most functions as points on the plane.
• This option is available in the Function Properties screen.

This quiz covers the basics of entering functions into graphing software. Learn how to format equations correctly, use codes for functions, and understand the role of spaces in determining function meaning. Perfect for beginners wanting to enhance their graphing skills.