<p>In my AP Calculus class, we are working on finding the Definite Integral. We have been taught a few ways, but the one I need help on is the use of trapezoids. I get the concept and understand how to do it but I can't program my calculator to do the function for me. My teacher provided us with the code to write the program, but it is only for the Ti-82 and Ti-83. As part of the class we are loaned the Ti-83 plus, but I have a Ti-89 Titanium and I really want to use my calculator. I tried to place the code he gave me into my calc but is says, "missing )". I have found a websie that allows you to download the TrapRule but for some reason, my computer is not recognizing that my Ti-89 Titanium is plugged into it. I downloaded the driver and everything and my computer even makes a noise when I connect the calculator. For some reason, when I open TI Connect and try to add data a little box appears and it says "com3 - not found" & "com 4 - not found". I have a test tomorrow, so if you can help me in any way please respond. If I can't figure it out, I'll just use the Ti-83 my teacher loaned me. Any type of help will be great.</p>
<p>The code was actually provided by the textbook.
Below is the code the teacher provided for the Ti-82 & Ti-83 (It definitely works on the Ti-83 plus):</p>
<p>:Prompt A
:Prompt B
:Prompt N
: (B-A)/N sto D
:0 sto S
:A sto X
:Y1/2 sto S //y1 divided by 2//
:For(K,1,N-1,1)
:X + D sto X
:Y1 + S sto S
: Disp Y1
:End
:B sto X
:Y1/2 + S sto S //y1 divided by 2 + S//
:SD sto I
: Disp "INTEGRAL"
: Disp I</p>
<p>Wait, if you just want to integrate the area for a trapezoid graphed on a standard (x,y) plane... can't you just go ahead and break it up into geometric shapes such as triangles and squares? (Or, heaven forbid, .5h(b1+b2)?)</p>
<p>I mean... unless you're doing something like revolving it around an axis or something (which it doesn't appear so)... the definite integral of a geometric shape should not require a calculator program... </p>
<p>Heck, a lot of what you do in calculus you won't be using a calculator for... why use it for something so silly now?</p>
<p>Sorry if I misunderstood your problem!</p>
<p>No, your answer didnt really help. Here's a problem from one of our practice tests.</p>
<p>Given the quadratic function f(x) = -0.5x^2 + 1.8x + 4. Approximate the definite intergal of f(x) from x = 1 to x = 4, by using trapezoids of width 0.5 unit.</p>
<p>The program above does this problem for you. a = 1 b = 4 n = 8</p>
<p>The answer comes out to 14.965. Some questions on the definite integral gives you a set of data, a graph, or a function. For the problems that provide you with a function, the program is a quick and easy way to find the answer.</p>
<p>I just want to know if anybody has the code for this program to work on the Ti-89 Titanium.</p>
<p>dude, all "missing )" means is that you made a typo in your code - specifically, you have a left parenthesis that was never closed with a right parenthesis. ti-basic is very similar between ti-83 and ti-89, so your code should work. just double check the program</p>
<p>
[quote]
Given the quadratic function f(x) = -0.5x^2 + 1.8x + 4. Approximate the definite intergal of f(x) from x = 1 to x = 4, by using trapezoids of width 0.5 unit.</p>
<p>The program above does this problem for you. a = 1 b = 4 n = 8
[/quote]
Shouldn't n=6 to yield half unit steps over the inclusive interval 1 through 4?</p>
<p>So:
x :: f(x)
1.0 5.3
1.5 5.575
2.0 5.6
2.5 5.375
3.0 4.9
3.5 4.175
4.0 3.2</p>
<p>Yields 6 trapezoids equivalent to in area rectangles width 0.5 and average height (f(x)+f(x + 0.5))/2 for x = 1.0 to 3.5</p>
<p>and a sum of 14.938.</p>
<p>n = 8 its just 4/.5</p>
<p>I found a program that works for the Ti-89 titanium. Thanks for the help anyway. The program does not work exactly like the one above but it gives me the answer I need so it's fine.</p>