## Sunday, November 8, 2015

### HP Prime Geometry App Tutorial Part 5: Plotting Functions and Differential Equations

HP Prime Geometry App Tutorial Part 5:  Plotting Functions and Differential Equations

The Geometry App can plot functions, parametric functions, polar functions, sequences, implicit statements, slope-field and ordinary differential equations, lists, and designate sliders.

In this lesson, we will demonstrate three types of plots.   For the purpose of the tutorial, clear the Plot screen before each example.

Plotting Functions ( y = f(x))

Plot y = e^x + 1.

1.  Press (Cmds), 6 for Plot, 1 for Function.
2.  Type e^(x) + 1.  Press (OK).

Use the lowercase x.  The format is plotfunc( y(x) ).

Plot an Ordinary Differential Equation  (y’ = dy/dx = f(x,y))

Plot y’ = y*e^x +1 with the initial condition (1,1).

1.  Press (Cmds), 6 for Plot, 7 for ODE.
2.  Type y*e^(x)+1.   Note that x and y are in lowercase.
3.  Press [ , ] and type [x,y].   Here you designate which variable is independent and which is dependent.
4.  Press [ , ] and type  [1,1].  This is your initial conditions.  Press (OK),

The entire format is plotode( f(x,y),  [x, y], [x0, y0])

Plot a Parametric Equation  ( x(t) + i*y(t) where i = √-1)

Plot x = 3t + 1, y = 2t – 1.   The format to be used is (3t + 1) + i*(2t -1).

‘1. Press (Cmds), 6 for Plot, 2 for Parametric.
‘2. Type (3t + 1) + i*(2t -1) and press ( OK ).

The entire format is plotparam( x(t) + i*y(t), var = tbeg..tend, tstep=step).  The t is in lowercase and the last two arguments, interval and step, are optional.

In Part 6 we’ll be plotting and working with polygons.   Thanks and take care,

Eddie

This blog is property of Edward Shore.  2015.

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