vv

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@gawati2611 

In this case you can simply plot  Re(z)>0, |z| > 1.
But note that inequal also accepts boolean operators, such that the region can be as complicated as you want (see the help pages).

@Preben Alsholm 

Nice catch! I remember that long time ago, such bugs were much easier to detect. Now, there are Maple fundamental functions which are implemented in a strange and undocumented manner. Of course, most of these functions are not designed to be used directly by the user, but it would be nice to know something about them. For example, some of such functions (including a part of the assume facility)  are in the Physics package, where almost everything is redefined.

@mmcdara 

restart

The parametrization of the intersection, including the ranges, is contained in the result of solve (see below).
It can be extracted programatically, but I did not have the patience to do it in general.

with(plots):

cylx := y^2 + z^2 - 1:

cylz := x^2 + (y+1)^2 - 1/2:

cyl:=implicitplot3d([cylx,cylz], x=-2..2, y=-2..2, z=-2..2,
scaling=constrained, style=surface, grid=[40, 40, 40], labels=[x, y, z], color=blue, transparency=0.5):
display(cyl):

opt:=thickness=4, scaling=constrained, style=surface:

s:=solve([cylx,cylz, x^2>=0,y^2>=0,z^2>=0],[x,y,z], explicit);
 

[[x = -(1/2)*2^(1/2), y = -1, z = 0], [x < 0, -(1/2)*2^(1/2) < x, y = -1+(1/2)*(-4*x^2+2)^(1/2), z = -(1/2)*(4*x^2-2+4*(-4*x^2+2)^(1/2))^(1/2)], [x < 0, -(1/2)*2^(1/2) < x, y = -1+(1/2)*(-4*x^2+2)^(1/2), z = (1/2)*(4*x^2-2+4*(-4*x^2+2)^(1/2))^(1/2)], [x = 0, y = -1+(1/2)*2^(1/2), z = -(1/2)*(-2+4*2^(1/2))^(1/2)], [x = 0, y = -1+(1/2)*2^(1/2), z = (1/2)*(-2+4*2^(1/2))^(1/2)], [x < (1/2)*2^(1/2), 0 < x, y = -1+(1/2)*(-4*x^2+2)^(1/2), z = -(1/2)*(4*x^2-2+4*(-4*x^2+2)^(1/2))^(1/2)], [x < (1/2)*2^(1/2), 0 < x, y = -1+(1/2)*(-4*x^2+2)^(1/2), z = (1/2)*(4*x^2-2+4*(-4*x^2+2)^(1/2))^(1/2)], [x = (1/2)*2^(1/2), y = -1, z = 0]]

(1)

s2:=tubeplot([x,-1 + sqrt(-4*x^2 + 2)/2, -sqrt(4*x^2 - 2 + 4*sqrt(-4*x^2 + 2))/2], x=-sqrt(2)/2..0, radius=0.05, opt, color=red):
s3:=tubeplot([x,-1 + sqrt(-4*x^2 + 2)/2, sqrt(4*x^2 - 2 + 4*sqrt(-4*x^2 + 2))/2], x=-sqrt(2)/2..0, radius=0.05, opt, color=red):

s6:=tubeplot([x, -1 + sqrt(-4*x^2 + 2)/2,-sqrt(4*x^2 - 2 + 4*sqrt(-4*x^2 + 2))/2], x=0..sqrt(2)/2,radius=0.05, opt, color=red):
s7:=tubeplot([x, -1 + sqrt(-4*x^2 + 2)/2,sqrt(4*x^2 - 2 + 4*sqrt(-4*x^2 + 2))/2], x=0..sqrt(2)/2,radius=0.05, opt, color=red):

display(cyl, s2,s3,s6,s7);

 

 

 

@janhardo It is difficult to learn Maple when the examples involve unknown maths methods.
To be efficient, I suggest to solve first those problems for which the maths is clear for you. After that, your Maple knowledge will be good enough to approch other problems. Keep in mind that when solving a math problem in Maple (for which a direct command does not exist)  you will have to know/read/review the existing methods (or maybe to invent or rediscover them!) .

 

@janhardo 

You should approach such problems only if you know the mathematical aspects.
In this case: geometry and linear algebra, see

@Danial If you are interested in the exact solution, you could rewrite (by hand) the inequality as a system of polynomial inequalities and then call solve or SemiAlgebraic. Unfortunalely Maple is not able to do this automatically.

P.S. In general it is is not possible to visualize inequalities in 3D. Try e.g. 
(x^2+y^2+z^2-1)*(x^2+y^2+z^2-2)<=0.
 

@rameen hamood 

It is easy to write it by hand (which I suppose you should do). Or, execute

LinearAlgebra:-GenerateMatrix([x1+6*x2, -2*x2, -4*x1+2*x2], [x1,x2]);

and select the matrix.
 

@nm You are confusing the OP.  A is a 5x4 matrix, so A.x makes sense and is the column Vector: 
<2298, -531, -160, -503, 579>
 

@nm Your initial ode is 
(2*x+y)/(3-x+3*y^2) dx - dy = 0; # M = (2*x+y)/(3-x+3*y^2), N = -1

It is not exact.

 

@michalkvasnicka 

For a more robust approach see Acer's answer. But you should be aware than any CAS may fail to solve directly your problem. If you know the maths behind it and the CAS language you have big chances to get a result. If not, it remains to complain about it.

@Fancypants The points are not unique, you are missing a condition.
It's not difficult to give an example, e.g. all Lij equal to 1 or 2.

@Fancypants Initially, all Lij were known. Now you say that some are not known. It's not the same thing!
In your picture, P0, P2, P3 seem to be collinear. If true, the number of needed Lij known could be decreased by 1. In principle this number must be >= 10 for a unique solution, but not any 10 will guarantee the uniqueness. Anyway, in this case a symbolic solution is improbable. If your problem is numeric you have the possibility to use DirectSearch to solve the system.

@michalkvasnicka 

If you try to solve f = 0, where

f := x^2 + 2*x + floor(x^2 + x)-25;

Mathematica answers:  This system cannot be solved with the methods available to Solve.

In Maple do (using the presented method):

seq(solve({eval(f,[floor(x^2 + x)=n]), n<=x^2 + x, x^2 + x<n+1}), n=-1..20);

      {x = -1 + sqrt(15)}

 

@Carl Love

Yes, thank you. Actually I have an enhanced version. It was written immediatley after the module version, but I forgot to replace it. I did it now.

@vs140580  I don't understand what you are trying to obtain. After relabelling the graph looks as in your picyure. I use GraphTheory for computations, not for drawings.
 

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