# Grapher Help...

Discussion in 'Mac Apps and Mac App Store' started by cateariffic, Aug 25, 2008.

1. ### cateariffic macrumors newbie

Joined:
May 23, 2008
Location:
Eugene, OR
#1
I'm trying to teach myself calculus, and teach myself how to use a graphing utility. I've been told by friends that they've taken whole classes on how to use a graphing utility before taking a stinkin' class that uses one. Is this really necessary, or are these people who just aren't that interested in learning Calc?

This being said I keep stumbling on little stupid things that stop me from being able to learn stuff. Like at the moment I'm not able to figure out how to see a table of the points that I've plotted. That is to say I want to enter, for example, "y = x squared" and get a nice curved line, as well as a table that says "(-4,16), (-3,9) (-2,4)" et cetera...

I tried browsing and searching the help. No luck.

I had to e-mail a friend to find out where Grapher was. I kept searhing for "Graphing Utility," "Graphing Calculator..." Me and searches don't understand each other.

Cate

2. ### Cromulent macrumors 603

Joined:
Oct 2, 2006
Location:
The Land of Hope and Glory
#2
You should be able to see where the points are, and of course you can always work it out yourself. Don't forget when the program plots something like y = x^2 you are only seeing a small section of it. The graph extends to infinity on either side so having a table with a bunch of co-ordinates is rather meaningless.

3. ### cateariffic thread starter macrumors newbie

Joined:
May 23, 2008
Location:
Eugene, OR
#3
Right, but I was hoping to have a tidy little list for one, and for two it's hard to describe fractional points.

And well, it's a desire to appeal to the authority of the text book. The exercise in my book calls for me to understand how to do this specific task with my utility. I loathe not doing the exercises because they so often lead to understanding or being able to do something else later.

But thank you...

Cate

4. ### Cromulent macrumors 603

Joined:
Oct 2, 2006
Location:
The Land of Hope and Glory
#4
What is the exercise you need to do?

5. ### cateariffic thread starter macrumors newbie

Joined:
May 23, 2008
Location:
Eugene, OR
#5
Exercise

Well the exercise I was working on then was simply to make a table of intercepts of a particular graph, just to learn how to table intercepts.

Today I found out I could click on an intercept and that the point is described at the bottom of the screen.

I discovered that 'r' does not mean radius yesterday. I wonder if it means 'random,' after what I saw when I entered 'x squared plus y squared equals r squared'.

I'm also struggling to find how to enter an exponent of 4. (That is, how can I have an exponent other than the squared or cubed in the Equation Palette.)

Cate

P.S. And why does y = x cubed - x + 1 yield (-1.32,0) on a TI and (-1,0) on Grapher!?! It has something to do with the "ZERO" or "ROOT" feature on a TI.

It's just that this book is geared for people using a TI. It seems that ultimately Grapher is, well, prettier and simpler to use. Grapher's just not the center piece of this text book. I don't wanna use the TI!

6. ### TomM macrumors newbie

Joined:
Dec 6, 2007
#6
About Exercise

On the exponents you can enter y=x 4th power by typing y= x^4 where
the [shift] [6] keys will provide the "top hat". To enter something like
y = x cubed + 8, type y = x^3 [right arrow] [right arrow] + 8. If you don't hit the right arrow key twice you will get y = x (3+8) power.

x squared + y squared = r squared is the equation of a circle, with r
being the radius as you thought. It seems that you must specify a value
of r to avoid getting an infinite number of circles.

The curve for the x cubed equation crosses the x axis at x = -1.32 which
makes that value a root. Since the curve is not touching the x axis at
x = -1, I wouldn't think that value is a root. I'm not familiar with using
a TI to find roots, but it may be good to check that the sequence of key strokes and commands you used is correct.

Good luck,

TomM

7. ### iMacmatician macrumors 601

Joined:
Jul 20, 2008
#7
It should be (-1.32, 0). There aren't any other real roots.

8. ### cateariffic thread starter macrumors newbie

Joined:
May 23, 2008
Location:
Eugene, OR
#8
Why don't we have a stuffy way of saying 'y'all'?

Y'all, you guys, Ustedes were right. I had incorrectly entered the equation.

And the thing that is not a hat (^) was great. One need only press the right arrow once (in case anyone is desperately trying to save themselves keystrokes).

I had a dream last night that I was looking through the Equation Palette, there was a menu of functions, some had very swirly pretty patterns, and it was fun looking, but I couldn't find the simple thing I was looking for....

That has been my experience so far, looking for things and finding neat little things, but not having any success in finding the thing I was looking for.

So I was excited about the exponent thing and then looked up "Characters" in the help menu, and there found a page explaining several characters and operators, including the "hat" (^) for the radical and the underscore (_) for an index.

I have another question if ye guys, thou all's, if thees countenances are so designed, to answer more simple Grapher questions. How does one enter an equation and then give a variable a value. (Like in the Torus Knot equation one can clearly see p = 3.)

Thanks again...

Cate