How to graph a basic x,y point on Grapher

Bonjour,

For point ( 5 ; 2) you may use a complex equation : x + iy = 5 + 2i

or a vector x, y = 5, 2

it's easier than using a point set, and allows you to define first x0 = 5, y0 = 2 and plot x+iy = x0 + iy0

Enjoy,

YB24

i have a question for YB24. I am new to grapher and am using it for a class. I have been trying to use the find root option in the equation menu and when I do it doesn't give me the x-value for when y=0. It keeps giving me numbers around it but it doesn't say y=0

Bonjour Krisjboil,

I need a little more information to see what happened : a screen shot of the list of equation (left part of the Grapher window), the OS X 10.x.x version, the Grapher version please.

Thanks,

YB24

PS.

A good 83 pages "Instructions for Use - Grapher" is available with various examples on

<http://y.barois.free.fr/grapher/>

2nd answer to Krisboil.

I use OS X 10.8.4 Mountain Lion and Grapher 2.3. What happens with the menu "Equation… > Find Root ?

I tried several equations and I noticed that Grapher makes a first approach to the solution then stops computing.

For a better accuracy it is necessary to re-enter the calculated x value as new initial value.

A good example is y = x^2 - 1 roots are +1 and -1 Finding the root +1 : try initial values 0.9 0.99 0.999 etc., you'll get better values of x and y each time you add a new decimal 9.

With x = 0.999 999 99 —> y = 0 at last !

What is strange is not that y not equal to 0 because numerical calculations have some limits of accuracy, but the fact that Grapher seems to stop iterations too soon when computing roots.

The job is done but is not perfect, I that a new bug ? may be, but easy to avoid.

Increasing numerical accuracy and number of decimals in the Grapher Preferences don't make any change in root computation.

So long,

YB24

For just plotting x vs y, add a New Point Set, then edit the points.