@rlopez Very thank you

@rlopez 

Very thank you
but I want explicit solution as  points.
I use (solve) on some example it was ok, like this example,
solve({x+y=0,y^2-x=0},{x,y});
But it does not succesfully work with this example,
solve({sin(x)+y=0,y^2-x=0},{x,y});
and
solve({sin(x)+y=0,y^2-x=0},{x=0..6,y=0..6});

I want to find roots of nonlinear system  in the specific region for example when x=0 ..2Pi, y=0..Pi.

best regards

@tomleslie thank you

@Carl Love 

@tomleslie 

with(plots):
plot3d(sin(x)+cos(y),x=0..Pi,y=0..Pi);

contourplot(sin(x)+(1/2)*cos(y),x=0..2*Pi,y=0..2*Pi);

When I plot this function , I want spesial curves not all curves for example ,I went curve when y=2..4 and x=0..1 just.

best regards

@Christopher2222 

very thank you

@rlopez 

thank you for your help.

but I want more explanation. I want the results like a table but I get a different thing I did not understand.

my programme is

with(plottools):

plottools[getdata](plot(x^2-4, x=-3..3));

my plottools[getdata](plot(x^2-4, x=-3..3))[3];

@tomleslie

very thank you 

@Markiyan Hirnyk 

very thank you

@Christopher2222 

firstly thank you ,

But when I plot a line which passes through  a point . this line appears above the point but I want the point appears above the line.

linecolor

how can I make every initial condition with a different colour?

@Kitonum 

thank you