3.1.2  Symbolic constants

Standard constants in Xcas are built-in symbols, given in Table 3.1.

---

Symbol	Value
e (or %e)	the number e1
pi (or %pi)	the number π
infinity	unsigned ∞
+infinity (or inf)	+∞
-infinity (or -inf)	−∞
i (or %i)	the complex number 0+1·i
euler_gamma	Euler’s constant γ:=limn→∞(∑k=1n1/k−ln(n))

Table 3.1: Symbolic constants in Xcas

---

Since these numbers cannot be written exactly as standard decimal numbers, they are necessarily left unevaluated in exact results (see Section 2.5.4).

You can also use evalf (see Section 7.3.1), for example, to approximate one of the real-valued constants to as many decimal places as you want.