>> From: PierLuigi Zezza "pierluigi.zezza"
# I have some problems in understanding the behavior al Maple
> restart;
# Let us solve an equation with radicals
> eq:=a*x+sqrt(1-x^2)=0;
> assume(a,positive);
> sol:=[solve(eq,x)];
#
2
eq := a x + sqrt(1 - x ) = 0
1 1
sol := [-------------, - -------------]
2 2
sqrt(1 + a~ ) sqrt(1 + a~ )
# Maple find two solutions, the first one is wrong
> simplify(subs(x=sol[1],eq));
a~
2 ------------ = 0
2 1/2
(1 + a~ )
# The second is correct
> simplify(subs(x=sol[2],eq));
0 = 0
# The problem arises from "squaring" the radical and hence I try
> restart:
> with(RealDomain):
Warning, these protected names have been redefined and unprotected:
Im, Re, ^, arccos, arccosh, arccot, arccoth, arccsc, arccsch, arcsec,
arcsech, arcsin, arcsinh, arctan, arctanh, cos, cosh, cot, coth, csc,
csch, eval, exp, expand, limit, ln, log, sec, sech, signum, simplify,
sin, sinh, solve, sqrt, surd, tan, tanh
> eq:=a*x+sqrt(1-x^2)=0;
> assume(a,positive);
> sol:=solve(eq,x);
2
eq := a x + sqrt(1 - x ) = 0
1
sol := -------------
2
sqrt(1 + a~ )
# But in this way Maple finds only the wrong one and I do not understand
# way
# thanks
# gigi zezza
PierLuigi Zezza
"pzezza"
|
(NAG)
