Owner's Manual

Appendix A: Categorical Listing of Operations 805
DelVar CATALOG
DelVar var1 [, var2 ] [, var3 ] ...
Deletes the specified variables from memory.
2! a ¸ 2
(a+2)^2 ¸ 16
DelVar a ¸ Done
(a+2)^2 ¸ (a + 2)ñ
deSolve() MATH/Calculus menu
deSolve( 1stOr2ndOrderOde , independentVar ,
dependentVar ) ⇒
⇒⇒
⇒ a general solution
Returns an equation that explicitly or implicitly
specifies a general solution to the 1st- or 2nd-
order ordinary differential equation (ODE). In the
ODE:
• Use a prime symbol ( '
, press 2 È) to
denote the 1st derivative of the dependent
variable with respect to the independent
variable.
• Use two prime symbols to denote the
corresponding second derivative.
The ' symbol is used for derivatives within
deSolve() only. In other cases, use d ().
The general solution of a 1st-order equation
contains an arbitrary constant of the form @
k ,
where
k is an integer suffix from 1 through 255.
The suffix resets to 1 when you use
ClrHome or
ƒ
8: Clear Home. The solution of a 2nd-order
equation contains two such constants.
Note: To type a prime symbol (
' ), press
2
È.
deSolve(y''+2y'+y=x^2,x,y)¸
y=(@1øx+@2)ø
e
ë x
+xñì4øx+6
right(ans(1))! temp ¸
(@1øx+@2)ø
e
ë x
+xñì4øx+6
d (temp,x,2)+2ù d (temp,x)+tempìx^
2 ¸ 0
DelVar temp ¸ Done