Dear all,

I am trying to solve this inequality:

0 < 2*b^2*(10*K*a+3*K*b-sqrt((K+(2*K*a+1)/b)^2-4*K/b)*b+5)

for a.

However, I get to the error below:

Error, (in testeq) invalid arguments
does anyone know which mistake I am making?!!

what is this testeq?!

Dear all,

Is there any way to fill the upper region in plot3d?

e.g. if I put the filled option in 

plot3d(y^3+x^2, x = 0 .. 1, y = -1 .. 1, filled)

then the region between the x-y plane and my plot will be filled. What if I want to fill the upper region?

The reason is that I want to show the upper region is acceptable for me, but I couldn't find any other way. 

If you have any solutions for me, I appreciate it.

Dear all,

I know the solve command is somehow limited, and it cannot find the solution for all equations.

But I have two equations which must be solved and I am desperately looking for solutions!

My equations are listed below:

f1:= (1/2)*x + (2*alpha*beta*(x^2+3*y^2)^beta*x^2/(x^2+3*y^2) ) -(3/2)*y - (1/2)*alpha*(x^2+3*y^2)^beta = kappa*rho*c0^2

f2:=-(1/2)*y+ (2*alpha*beta*(x^2+3*y^2)^beta*y^2/(x^2+3*y^2) ) -(1/2)*x - (1/2)*alpha*(x^2+3*y^2)^beta = 0

I need to find x and y in terms of alpha and beta.

The other parameters are known.

But of course, maple gives me the warning: "Warning, solutions may have been lost".

Does anybody have any suggestion?

Dear all,

I am trying to solve a differential equation; 

diff(H(z), z) = 6.534101519*10^17*H(z)^2*(1.+z)^(5/2)+6.250000000*10^(-67)*sqrt(-1.639468135*10^119*H(z)^2*(1.+z)^5+9.161095674*10^82*(1.+z)^8+1.092978756*10^168*H(z)^4*(1.+z)^5)

sol := dsolve({test, H(0) = 2.268308490*10^(-18)}, numeric, range = 0 .. 3)

The problem is that it gives me the eror: 

Warning, cannot evaluate the solution further right of .25430145, probably a singularity

How can I get rid of this?

Dear friends,

I have a huge differential equation which I am trying to solve.

However, even solving it numerically, maple keeps evaluating it for a long time and then stops working! So there is no solution.

I just want to check if there is any solution to this differential equation at all!

Do you know a way with which maple can check if the differential equation is solvable?