Getting Startedwith MATLAB (part 3)

1. Algebra, 2. Trig3. The keyword ans4. Clean up and suppress output:

finalizing the software’s presentation

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1. Algebra

Precedence rules apply: 2+3 <enter> 2-6 <enter> 2*3 <enter> 7/3.5 <enter>

2+3*3 <enter> (2+3)*3 <enter> 5^2 <enter> i^2 <enter>

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2. Trigonometry

Why does sin(30) give a “wrong” answer? _________________________

2. Trigonometry

Common functions sin(), cos(), tan(), sind(), cosd(), tand(), asin(), acos(), atan(), asind(), acosd(), atand() exp(), sqrt(), log(), log10() abs(), round()

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3. The keyword ans

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3. The keyword ans

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3. The keyword ans

Next question: What is ans ? ____________7

4. Polishing the final product

clear <enter> typed inside the command window Will delete all the variables in the Workspace this time. There is

no going back. This cleans up every variable from memory. (No more little yellow boxes in the Workspace)

clc <enter> typed inside the command window Will completely erase the content of the command window. It

does not affect the Workspace - the variables still exist and can be used.

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“Suppressing” the output

Hiding intermediate results, or even initial variables

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No semi-colons…

“Suppressing” the output

Second version, with semi-colons

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Using a semicolon on these lines “suppresses the output”.

In other words, it does not show the result of the command.

But…did the commands do anything?

“Suppressing” the output

Still second version (with semi-colons)

11The variables ARE CREATED, and commands ARE executed!

“Suppressing” the output Since the result does not show up automatically in the

command window, to **recall** (i.e. show again) the variable: type area <enter> in the command window

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Wrapping Up Algebra reminders

Order of Operations: Parentheses Exponent Multiplication and Division are the same precedence Addition and Subtraction are the same precedence

Trigonometry MATLAB standard trig functions use radians by default

e.g. sin() uses radians; sind() uses degrees

Suppressing the output: Use a semi-colon at the end of calculations

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