First steps in

MathCad

MathCad is a computer algebra system. It is installed on all computers in the Computer Lab and in the Electronic classroom. You start it by doubleclicking the MathCad icon.

With MathCad you can type text, solve equations, define functions and graph them, differentiate and integrate them, and much more.

On the empty sheet that occurs when you open MathCad, you are supposed to put text regions and Math regions.

Click somewhere on the sheet, Type " and a small square shows. The region will now be a text region. Type some text to try it. Now click somewhere else and type something without typing first ". Then you will create a Math region. Type something like a:5 and a:=5 will show.

Moving regions

You can move regions around. Click somewhere on the sheet, keep the mouse pressed while approaching one of the two regions. A dashed rectangle is created, but when you hit the existing region, the border of it shows also dashed. Release the mouse. The whole procedure is called "drag-selecting the region". Now you can grab the region with the mouse and move it.

It is important to understand that MathCad only reads the Math regions, and it reads it like Western people would, in rows from left up to right down.

Try the following: Create another math region, under your first one, by typing a=. It will show a=5. Now if you graph this region and move it above the a:=5 region, the 5 will vanish. Up there, MathCad doesn't know yet what a is.

Three equation symbols

are used in MathCad. := for defining the value of a constant, or for defining functions (remember, you only type :). Secondly = for displaying values of constants or functions. Finally, and not so important at the moment, = (in bold) is for equations---you can find this (and also the other two) on the Evaluation and Boolean Palette.

Palettes

Just under the Menu Bar are buttons for different palettes . We need the Arithmetic (mostly for the radical symbols), the Evaluation and Boolean (for =), and the Calculus Palettes (for d/dx, integrals, and limits).

Variables and constants

are both abbreviated by letters or names, like x, y, z. It's a variable until you have

assigned a value, like in x:=3 from then on it is a constant, or
made it a range variable, like in x:=2,2.1..3, see below.

Formulas

Use ^ for exponentiation, * for multiplication, and also +, -, /. Use parentheses.

To get complicated formulas right is a little tricky, especially if exponents are involved. Always keep an eye on the cursor. To get one level higher (for instance from exponent to base, use the up arrow key .

Try typing a:x^2+3 and compare it to what you get by typing a:x^2+3. Also compare the results when typing a:x+2/x and a:x+2/x. You may also use the other arrow keys for navigating in complicated formulas.

Expressions which are numbers (contain only numbers and constants) you can evaluate with the =. If the expression contains variables, you can simplify it with Ctrl-. (ctrl-key, together with the point-key)

Placeholders

Small black rectangles are placeholders for variables or numbers. Click on them and replace them by what is needed.

Functions

Are defined by typing something like f(x):x^2+3*x-2, creating f(x):=x²+3x-2. Now type f(3)= und MathCad evaluates the function for you.

Erich Prisner, October 2003