Tuesday, December 17, 2013

HP Prime: CAS Commands in Home Mode

(Common) CAS Commands in Home Mode
(udpated 4/17/2014)

Two things to aware of:

1. Any command from the CAS mode to be used in the Home Mode, regardless of entry, must have a "CAS." prefix. Examples include CAS.diff, CAS.simplify, etc.
2. Algebraic (symbolic) objects need single quotes surrounding them. They can be called by pressing Shift+Parenthesis Key ().
3. Not all CAS commands work as expected in Home and Programming. My focus is on the Home mode.

Simplify: CAS, 1, 1

Non-RPN: CAS.simplify('expression')
RPN: Not recommended - as it will numerically evaluate the expression

Expand: CAS, 1, 3

Syntax: CAS.expand('expression')
RPN: Not recommended - as it will numerically evaluate the expression

Example: CAS.expand('(X+3)^2') returns X^2+6*X+9

There are two commands for factoring:

Polynomial: CAS.Factor: CAS, 1, 4
Non-RPN Syntax: CAS.factor('expression')
Example: CAS.Factor('X^2-5*X+4') returns (X-4)*(X-1)

Integer: CAS.ifactor: CAS, 5, 2
Non-RPN Syntax: CAS.ifactor(integer)
Example: CAS.ifactor(186) returns 2*3*31

RPN Syntax:
1: integer
CAS.ifactor(1), press Enter

Differentiation: CAS, 2, 1
Non-RPN Syntax: CAS.diff('expression')

Simplification may be needed. So call up CAS.simplify, put up single quotes using Shift+Parenthesis Key, key up to the expression, press Copy (soft key), then press Enter

CAS.diff('COS(X)*SIN(X)') returns -SIN(X)*SIN(X)+COS(X)*COS(X)
CAS.simplify('-SIN(X)*SIN(X)+COS(X)*COS(X)') returns 2*COS(X)^2-1

RPN Syntax:
1: 'f(X)'
CAS.diff(1), press Enter

Update (4/17/2014):  If the above does not work, try this syntax:

CAS.diff('expression', 'variable')  

Example:  CAS.diff('COS(X)*SIN(X)', 'X') returns  -SIN(X)*SIN(X)+COS(X)*COS(X)

2:  'expression'
1:  'variable'
CAS.diff(2), press enter

Integration: CAS, 2, 2
Non-RPN Syntax: CAS.int('expression')

Simplification may be needed. So call up CAS.simplify, put up single quotes using Shift+Parenthesis Key, key up to the expression, press Copy (soft key), then press Enter

CAS.int('2*e^(4*X)') returns 2*e^(4*X)/4
CAS.simplify('2*e^(4*X)/4') returns e^(4*X)/2

Not recommended for RPN Entry

Update (4/17/2014):  If the above syntax does not work, try:

CAS.int('expression', 'variable')

CAS.int('2*X*e^(4*X)','X') returns 2*(4*X-1)/16*e^(4*X)
CAS.simplify('2*(4*X-1)/16*e^(4*X)') returns (4*X*e^(4*X) - e^(4*X))/8

Summation (Σ): CAS, 2, 5
Non-RPN Syntax: CAS.sum('expression', 'variable', start, end)
Example: CAS.sum('N^3','N',1,9) returns 2025

RPN Syntax:
4: 'expression'
3: 'variable'
2: start
1: end
CAS.sum(4) press Enter

Note: Start and End must be numerical limits.


I recommend zeros and cZeros, not solve and cSolve. The syntax is pretty much the same.

zeros: CAS, 3, 2
cZeros: CAS, 3, 4

If the equation is f(X) and we are solving for X:

Non-RPN Syntax: CAS.zeros('f(X)')

RPN Syntax:
1: 'f(X)'
CAS.zeros(1), press Enter

CAS.zeros('X^3-6') returns [1.81712059283]

If you are solving for variables other than X:

Non-RPN Syntax: CAS.zeros('expression', 'variable')

RPN Syntax:
2: 'expression'
1: 'variable'
CAS.zeros(2), press Enter

Got to include the variable!

CAS.zeros('R^3-6') returns [].
CAS.zeros('R^3-6','R') returns [1.81712059293]

Hope this helps and we will cover more of this subject in the future.


This blog is property of Edward Shore. 2013


  1. Thank you Eddie for showing how to prepare and execute some CAS commands in the Home mode.

    However, after keying in most of these on the calculator, it felt slow and error prone versus just using CAS mode.

    RPN (where CAS supported) seemed almost as quick as CAS mode.

    1. I wish the RPN mode wasn't so limited in CAS abilities.

  2. Help: As advised, in home mode I enter CAS.diff('COS(X)*SIN(X)') but the calculator returns "0" instead of the differentiated function. This is typical of my results. My version info is 2013 11 25 (5447), CAS version 1.1.0-27

    1. Try CAS.diff('COS(X)*SIN(X)','X') Hopefully that will work with Ver. 5447.

      Since this blog entry was done with an earlier software version, I may be looking at updating this entry. Thanks,


  3. Thank for you. That worked beautifully. I might add that "Complex" needs to be unchecked to get the result you show. I'm a new owner going through painful acclimation. Love your blog. JFS.

  4. Thanks Eddie for your insight. I was playing around with my new HP Prime and thought I would tackle something benign like Newton's method. I'm just not getting the syntax to call CAS.diff on my function defined as F1(x) in the Function Symbolic View for each of the iterations. I've tried "f := CAS.diff('F1','X');" but to no avail. Do you have ideas on this?

    1. Sorry for getting back to you so late.

      On the Function App, Symb View, what you want is to use the Derivative template. The Derivative Template on the top row, 4th column on the template touch menu.

      Set up: F1(X) = (d f(T))/(d T = X)

      d is the derivative symbol
      T is a dummy variable

      Example: (d T^3)/(d T = X)

      Video on calculating derivatives on the HP Prime (general): https://www.youtube.com/watch?v=LXwLiPlKO2M&list=UU25vsJdvgf_doIgE8-Lu7Xw

      Hope this helps, again, apologizes for being super late. :(



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