# Difference between revisions of "Formula plotting-special symbols"

Click here for examples to see how special symbols are used. Examples are accompanied by source code and are rather self explanatory.

Special symbols refer to math elements that are displayed by locating formula elements in peculiar ways. Regular functions like sin(x) are not mentioned here. Only things that are plotted in a special ways, like integrals and logarithms, are discussed here.

• Sums are entered using a "sum" function
``` sum( from, to, expression )   <-- sum with limits
sum( expression )             <-- sum without limits
```

Example:

``` e=sum( i=0, N, 1/i! )
sum( 1/i ) = infinity
```
• Integrals are similar to sums and are entered using the 'int' symbol
``` int( expression, dx, from, to )   <- integral with limits
int( expression, dx )             <- integral without limits (undetermined)
```

Example:

``` int( 1/x^2, dx, 1, infinity )
int( e^(x^2/2), dx )
```
• greek letters are entered using their common English names. Lowercase names mean lowercase greek letters, uppercase names mean uppercase greek letters. Example: epsilon, EPSILON, pi, PI. See examples link in the first paragraph.
• The infinity symbol is entered as 'infinity'.
• logarithms are entered using either base and power, or just power; Examples:
``` log( 2, 8 ) = 3
log( xy ) = log( x ) + log( y )
```
• square roots are entered using 'sqrt'. Example
``` sqrt( b^2-4ac )
```
• limit is entered using the "lim" notation:
``` lim( x->infinity, 1/x )
df/dx = lim( DELTA->0, (f(x+DELTA)-f(x))/DELTA) )
```