Our CAS calculators are a powerful (and very expensive) tool. They are such sophisticated devices that can do pretty much everything in maths we ask of it!

However, a lot of students struggle with all the functions included in them. Knowing how to properly use your calculator is essential for success in Methods. After all, your final Year 12 Calculator Active exam is worth 40% of your overall score!

Throughout the year, you should really prioritise time to learn how to use the calculator to your advantage. To help you begin, here are the top 8 things you should know how to do on your CAS.

Note: This guide will cover the functions for both the TI-Nspire and Casio Classpad. All calculations on the TI-Nspire can be done in ‘A. Calculate’. and on the Classpad, they can be done in the Main Menu.  

1. Solving Algebraic Equations

The ‘solve’ command on both calculators is extremely useful, especially when you get some very long winded equations.

On Classpad: KeyboardàMath 1à Last box, Third Row (Called ‘Solve()

On TI-Nspire: Menuà3. AlgebraàSolve

After inserting the function, type in your equation. Then insert a comma and the variable that you need to solve for. Close it all off with another bracket and press enter to get your answer.

2. Specifying Domains

Have you ever tried to solve a trigonometric equation, only to get some wacky answer involving ‘constant’ or some random variable?

Well, this can be easily rectified by specifying the domain that you want to solve the equation for. This isn't limited to trigonometric functions though, you can even use it when you want the calculator just to give you positive answers or similar.  

On Classpad/TI-Nspire: First type in the equation with the ‘solve’ function as you normally would. Then, insert a vertical line. After the vertical line, just specify your domain for the variable you used, using greater than and less than signs.

Vertical Line on Classpad: KeyboardàMath 3 àLast Box, Fourth Row.

Vertical Line on TI-Nspire: ctrlà=àSelect the line on the window that appears

3. Defining Functions

VCAA loves to throw in questions on the Tech Active Exam which involve so many different parts. Usually, with these types of questions, all the parts involve the same function. Therefore, to save you from typing in the function each time you need it, you can just define it with a single variable and type that instead.  

On Classpad: InteractiveàDefine (Right at the bottom of the list)

The Func Name is what you want to refer to the function as, and the variable is what the function depends on. Type out your expression in the third box.

On TI-Nspire: Menuà1:Actionsà1:Define

The ‘Define,’ function will appear on a command line. From this point, you just need to enter the function using function notation (i.e.f(x)=……).

4. Expanding/Factorising Equations

This is very useful when you’re required to expand multiple sets of brackets or factorise complicated expressions.  

On Classpad:

To expand an expression: InteractiveàTransformationàExpand

To factorise: Interactiveà TransformationàFactoràFactor

On TI-Nspire:

To expand an expression: Menuà3.Algebraà3.Expand

To factorise: Menuà 3.Algebraà2.Factor

5. Graphical Analysis

In Methods, you will be required to sketch a lot of different graphs, some of which are too hard to sketch by hand. Therefore, knowing all the features of the graphing screen on your calculator is so important!

On Classpad: Press on ‘Graph and Table.’

Type out the name of your function where it says ‘y1..y2 etc.’ Press the button on the top left hand side of the screen to sketch out the graph.

Axis Intercepts: AnalysisàG-SolveàRoot OR y-intercept

To find a pair of coordinates on your graph: AnalysisàG-Solveàx-cal/y-cal

Points of Intersection: AnalysisàG-SolveàIntersection

On TI-Nspire: Open the Graphing window

Type your function into the ‘f1(x)=’ line and press enter. If you want to graph multiple functions, press: MenuàGraph Entry/Edità1:Function.

Axis Intercepts: 6. Analyse Graphà1. Zeros

Points of Intersection: Menuà6. Analyse Graphà4. Intersection

6. Simplifying Equations

If you want to get the calculator to combine multiple algebraic fractions, or expand and factorise at the same time, you can use the ‘simplify’ function.

On Classpad: Interactive à Transformation à Simplify.

After inserting the simplify function just type out the function you want to simplify in the window that pops up, then press enter.

7. Converting Between Decimal and Exact Form

Remember when you lost marks on your test for not leaving your answer in exact form? Well, thankfully our calculators can convert between the two forms.

On Classpad: After typing in the value that you want to convert, just press the button underneath the settings sign in the top left corner.

On TI-Nspire: Menuà2.Numberà1. Convert to Decimal OR 2. Approximate to Fraction

8. Solving Simultaneous Equations

You’re sitting a TA exam and you see the following question.

‘What are the values of a, b and c that make the following equations true?’

2a/11+6b-c=24

7a-5b/7-2c=32

0.5a+7b+8c=28

You begin solving them by hand and get nowhere. Well, lucky for us, our calculators can solve the equations for us! It doesn’t matter how many equations you have in the system – if you use enough variables, the calculator has got your back!

On Classpad: Press KeyboardàMath 1à Third Box, Fourth Row

The function will automatically insert two lines for you to write the equation in. On the right side of the line, you can type out the variables you want to solve for, separated by a comma. 

On TI-Inspire: Menuà3. AlgebraàSolve

After inserting the solve command, press the button on the right hand side of the number 9 button on the keyboard. You can type in the equations you want to solve on each line that appears.

After typing in the equations that you want to solve, insert a comma. Then, write out the variables that you want the value to, separated by another comma. 

On both calculators, if you want to add more equations, simply press the function button again.

Try solving this system on your calculator. What answers did you get for a, b and c?

Your calculator is one of the most powerful tools you have alongside you, and it really has the potential to become your greatest saviour in Methods. Therefore, make sure you spend lots of time getting to know it and all that it can do. There’s a lot more that the calculator can do compared to the things outlined here, but hopefully these tips will help you get started!

If you would like to download a set of free notes, that summarise all these tips, you can do so here.