Symbolics > Symbolic Evaluation > Evaluating Functions Symbolically
Evaluating Functions Symbolically
When you evaluate a function using the symbolic evaluation operator, PTC Mathcad substitutes the argument into the function and evaluates it symbolically.
You can use a symbolic expression as a function argument, as follows:
You can also symbolically evaluate the standard PTC Mathcad operators and many built-in functions, including most common numerical functions such as sin(x) and ex.
To apply a function to a vector and evaluate the function symbolically, use the vectorize operator. For example, to compute the cosine of each entry of the following vector, apply the vectorize operator to the cos(v) function as follows:
 v
3 π 2
π 4
π 3
cos v 0
2 2
1 2
Some built-in functions retain their usual meanings in symbolic calculations, but many do not have any meaning in the symbolic context and are not evaluated. A few of these functions have different meanings or restrictions under symbolic evaluation:
Unlike the numerical mod function, the symbolic mod function requires an integer modulus, and it can accept a polynomial as its first argument.
Certain symbolic inverse trigonometric functions use different branches in the complex plane.
The eigenvals function calculates symbolically for complex and real matrices.