I have been involved in programming TI89s for over 10 years

All posts by ti89guru

Jacobian and Hessian Matrix using the TI89 in Calculus

Finding the Jacobian and Hessian Matrix using the TI89 is done with Calculus Made Easy from www.Ti89.com  navigating to the Multivariable Calculus menu under F6, then go to F3 to select Find Jacobian or Hessian. Check the screenshots below. To enter a vector-valued function use  [ , ]  notation to enter it on a TI89…. (read more)

Compute Mean, Mode, Median, Average, Standard Deviation, Range with a TI89 Calculator

Here is the quick way to find Mean, Mode, Median, Average, Standard Deviation, Variance, Range and more using the trusted TI89 : Just enter the list of numbers as shown in the image above. Press ENTER and Voila, all values are shown immediately. This is part of the comprehensive Statistics Made Easy app for the… (read more)

TI89 Titanium Cheat Sheets , Shortcut Keys, Custom Menus and Rename Programs

We have listed the following useful information at https://www.ti89.com/resources.php : TI89 Cheat Sheets Shortcut Keys Custom Menus Rename Programs This is a MUST KNOW for every savvy TI89 user: Learn how to use the TI89 efficiently by pressing the right buttons without searching. Did you know you can actually easily create you own custom menus… (read more)

How to Connect a Ti89 Calculator to Mac Computers using TI-Connect v4.1

Here is a proven way for those of you that struggle to connect your Ti89 calculator to a MAC computer. This is what you need to do to get connected: Uninstall TI Connect v4.0 if installed. Download and Install TI Connect version 4.1  : https://education.ti.com/ticonnect/ticonnectmac41 . Beware: this link immediately downloads the .dmg file to your… (read more)

Laplace Transform Information using TI89’s Differential Equations Made Easy

To find the Laplace Transform of a piecewise defined function , select Laplace Transform in the Main Menu, next select option3 “Piecewise defined function” in the dropdown menu as shown below: Next, enter the two pieces/functions as shown below. c is the breakpoint. 2) To SOLVE a Differential Equation using LaPlace Tranforms such as y”+2y’+y=0… (read more)

Not only are these apps a life saver but when, the costumer service was even more impressive

I downloaded linear algebra and the physics made easy apps and I love them both !!!!! They are incredibly user friendly and helped me a ton, I just got a 100 on my linear algebra test using this app! Not only are these apps a life saver but when I had a question regarding downloading… (read more)

Balancing a chemical equation using the TInspire CAS CX and the Chemistry Made Easy app – step by step

Here is a solved example: When balancing the chemical equation: Fe2S3+O2=Fe2O3+SO2 The setup is a_*Fe2S3+b_*O2=c_*Fe2O3+d_*SO2 or : a_*(2Fe+3S)+b_*(2O)=c_*(2Fe+3O)+d_*(1S+2O) This sets up : 2*a_=2*c_ and 3*a_=d_ and 2*b_=3*c_+2*d_ which has the solution : {a_,b_,c_,d_}={2,9,2,6} Thus, 2*Fe2S3+9*O2=2*Fe2O3+6*SO2 —

The customer service at CME is fantastic and The Riemann sum section is especially good.

The customer service at TI89.com is fantastic, they replied in a very timely manner. This kind of service is rare. I am using the Calculus Made Easy app I use the app a great deal in checking work and to perform investigations. The Riemann sum section is especially good.

Love the TI89 Physics & Differential Equations Made Easy Apps PLUS: Outstanding Customer Service

I originally found the ti89.com website by surfing the web trying to find ways to help with my physics class. After downloading my first app I loved it! Helped in so many ways especially when they do step by step. I downloaded my second app a year later taking my differential equation class. It easily… (read more)

Chemistry App for the TiNspire CX at www.TiNSpireApps.com has Bases, Acids, Equilibrium, Valence Electrons

It seems that the Stoichiometry section of our Step by Step Chemistry App has doubled over the last few months, lots of new computational Chemistry has been added. Find app updates below: – Valence Electrons of Atoms and Molecules – Equilibrium Constant Kc – Equilibrium Composition – Kp = Kc*(RT)^n – Equilibrium of weak bases… (read more)