With one exception, you perform calculations in CAS view just as you do in Home view. (The exception is that there is no RPN entry mode in CAS view, just algebraic and textbook modes). All the keys work in the same way in CAS view as Home view. The primary difference is that the default display of answers is symbolic rather than numeric.
You can also use the template key (F) to help you insert the framework for common calculations (and for vectors and matrices). This is explained in detail in “Math template” on page 21.
The most commonly used CAS functions are available from the CAS menu, one of the Toolbox menus. To display the menu, press D. (If the CAS menu is not open by default, tap
.) Other CAS
commands are available from the CATLG menu (another of the Toolbox menus).
To choose a function, select a category and then a command.
Example 1 To find the roots of 2x2 + 3x – 2:
1. With the CAS menu open, select Polynomial and then Find Roots.
The function proot() appears on the entry line.
2. Between the parentheses, enter:
2ASsj+
3ASsw2
3. Press E.
Example 2 To find the area under the graph of 5x2 – 6 between x =1 and x = 3:
1. With the CAS menu open, select Calculus and then Integrate.
The function int() appears on the entry line.
2. Between the parentheses, enter:
5ASsjw 6oASso 1o3
3. Press E.
Settings
Various settings allow you to configure how the CAS works. To display the settings, press SK. The modes are spread across two pages.
Page 1
Setting Purpose
Angle Measure Select the units for angle measure-ments: Radians or Degrees.
Number Format (first drop-down list)
Select the number format for dis-played solutions:
Standard or Scientific or Engineering
Number Format (second drop-down list)
Select the number of digits to dis-play in approximate mode (man-tissa + exponent).
Integers
(drop-down list) Select the integer base:
Decimal (base 10) Hex (base 16) Octal (base 8) Integers (check
box) If checked, any real number equiv-alent to an integer in a non-CAS environment will be converted to an integer in the CAS. (Real num-bers not equivalent to integers are treated as real numbers in CAS whether or not this option is selected.)
Exact If checked, the calculator is in exact mode and solutions will be symbolic. If not checked, the calcu-lator is in approximate mode and solutions will be approximate. For example, 26n5 yields in exact mode and 5.2 in approxi-mate mode.
Complex Select this to allow complex results in variables.
Use √ If checked, second order polyno-mials are factorized in complex mode or in real mode if the dis-criminant is positive.
Setting Purpose (Cont.)
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Use i If checked, the calculator is in complex mode and complex solu-tions will be displayed when they exist. If not checked, the calculator is in real mode and only real solu-tions will be displayed. For exam-ple, factors(x4–1) yields
(–1+x),(1+x),(i+x),(–i+x) in com-plex mode and
(–1+x),(1+x),(1+x2) in real mode.
Principal If checked, the principal solutions to trigonometric functions will be displayed. If not checked, the gen-eral solutions to trigonometric func-tions will be displayed.
Increasing If checked, polynomials will be displayed with increasing powers (for example, –4+x+3x2+x3). If not checked, polynomials will be dis-played with decreasing powers (for example, x3+3x2+x–4).
Setting Purpose (Cont.)
Setting Purpose
Recursive
Evaluation Specify the maximum number of embedded variables allowed in an interactive evaluation. See also Recursive Replacement below.
Recursive
Replacement Specify the maximum number of embedded variables allowed in a single evaluation in a program.
See also Recursive Evalua-tion above.
Recursive
Function Specify the maximum number of embedded function calls allowed.
Setting the form
of menu items One setting that affects the CAS is made outside the CAS Settings screen. This setting determines whether the commands on the CAS menu are presented descriptively or by their command name. Here are some examples of identical functions that are presently differently depending on what presentation mode you select:
The default menu presentation mode is to provide the descriptive names for the CAS functions. If you prefer the functions to be presented by their command name, deselect the Menu Display option on the second page of the Home Settings screen (see “Home settings” on page 27).
To use an expression or result from Home view
When your are working in CAS, you can retrieve an expres-sion or result from Home view by tapping Z and selecting Get from Home. Home view opens. Press = or \ until the item you want to retrieve is highlighted and press E. Epsilon Any number smaller than the
value specified for epsilon will be shown as zero.
Probability Specify the maximum probability of an answer being wrong for non-deterministic algorithms. Set this to zero for deterministic algo-rithms.
Newton Specify the maximum number of iterations when using the Newto-nian method to find the roots of a quadratic.
Setting Purpose (Cont.)
Descriptive name Command name
Factors List ifactors
Complex Zeros cZeros
Groebner Basis gbasis
Factor by Degree factor_xn
Find Roots proot
The highlighted item is copied to the cursor point in CAS.
To use a Home
variable in CAS You can access Home variables from within the CAS. Home variables are assigned uppercase letters; CAS variables are assigned lowercase letters. Thus SIN(x) and SIN(X) will yield different results.
To use a Home variable in the CAS, simply include its name in a calculation. For example, suppose in Home view you have assigned variable Q to 100. Suppose too that you have assigned variable q to 1000 in the CAS. If you are in the CAS and enter 5*q, the result is 5000. If had entered 5*Q instead, the result would be 500.
In a similar way, CAS variables can be used in calculations in Home view. Thus you can enter 5*q in Home view and get 500, even though q is a CAS variable.