<p>How do I do that? Let's say I have 3 equations with 3 unknowns. How about 3 equations with four unknowns? Instead of using matrices, can I just use one of the function in the calculator to do that?</p>
<p>Yeah. Use the solve function in F2. Then put in each equation, and separate them by using "and" (in the catolog). Now solve for only 1 variable, and all the values will come up.</p>
<p>Example just in case you didn't catch that fully:</p>
<p>x + 2y = 3
y + x^2 = 6</p>
<p>solve(x + 2y = 3 and y + x^2 = 6, x)</p>
<p>and that does it!</p>
<p>Thanks! I always the comma instead of the and, thats why I messed up! :)</p>
<p>I got a problem-- I did what was told but got the mssage "Argument must be a Boolean expression or integer" ?!?</p>
<p>Did you forget an "=" sign somewhere?</p>
<p>.. I forgot a equal sign.. sorry </p>
<p>One more question--how can I tell which variable will have an infinite number of solution, so that I know how to express the other ones in terms of that variable?</p>
<p>Fro ex:</p>
<p>2x-y+z=-1
x+3y-2z=2
-5x+6y-5z=5</p>
<p>Using matrices I found that z can be any real #, so I expressed x and y in terms of z. Without doing matrices, how do I know z can have infnite solutions??</p>
<p>Thanls!!!!</p>
<p>Help please.. that will be my last question, I promise :)</p>
<p>do you just type in "and" using the letter keys?</p>
<p>Go to "Catalog" and hit the = button (hit that because the = button is the same as the "A" button), which I believe will select "and".</p>
<p>I suppose you could just type it out, as well, but if you do that, make sure you put a space before and after. </p>
<p>It's easier to get it from the catalog.</p>
<p>Bump.. Can somebody help me with my last question? OR does my last question have no answer?? Tell me something, anything!</p>
<p>These are better solved by hand. Anyways, use a matrix with the 89.</p>
<p>Oh yeah, doing it by hand's alot easier...PSYCHE!</p>
<p>Sure, who wouldn't love to solve a systems of equations in 10 minutes instead of 30 seconds, I would, wouldn't you!? (lol... :D)</p>
<p>Without using matrices, there is probably not a way to find out specifically if the value of "z" has an infinite number of solutions (but I haven't had AP calc yet either :) )</p>
<ul>
<li>Yes, just type "and" with spaces before and after between equations and solve for the variable you want, or get it from the catalog.</li>
</ul>
<p>:D</p>
<p>"One more question--how can I tell which variable will have an infinite number of solution, so that I know how to express the other ones in terms of that variable?"</p>
<p>In your example, the solution to the system looks like this:</p>
<p>x=-1/7-t/7
y=5/7+5t/7
z=t
Where t can be any real number</p>
<p>As you can tell, each variable can take on an infinite number of values. Thus, rather than saying an individual variable has infinite solutions, you should say the system has infinite solutions. You may think this is petty. However, consider another set of solutions to the same system:</p>
<p>x=s
y=-5s
z=-1-7s
where s can be any real number</p>
<p>You find that these two sets of solutions are identical.</p>
<p>Hope this clears up the general understanding of the solution. It is a topic (including the link between the two solutions) covered in great depth in linear algebra.</p>
<p>Why do all of you guys have TI-89's? Don't they cost around $200 dollars!<br>
Next year I am taking BC and adv. physics and only about 1 in 20 kids in those classes will have a TI-89, I just don't see its use. Besides on Ap's most of it is done calc free.</p>
<p>i got mine for $100 on ebay</p>
<p>@tbry23m: You can pick them up for about $40-60 on craigslist. And they’re amazing. You will use one all throughout college if you plan on doing any kind of science, math, or engineering. I use mine every bloody day. 3D graphing, solving variable functions, cross and dot products, matrices, etc. It’s pretty powerful, and it will greatly simplify your life by learning it (if you’re something like an art history major or a business major though, yeah, you just need a pencil and maybe some paint).</p>