Advanced Search

umar khan

30 Reputation

5 Badges

8 years, 235 days
Contact umar khan

MaplePrimes Activity


These are questions asked by umar khan

how do we plot the graph of y(x) also wh...

umar khan 30 Maple
plot syntax rootfinding
December 05 2016
1 2


 

> 

restart
> 

G := 6.6743*10^(-8); 1; R := 1336599.126346; 1; rho := 2.2450*10^14; 1; c := 2.9799*10^10; 1; a := 1/(8/3*(6.67*10^(-8)*Pi*rho/c^2))^.5

0.6674300000e-7

  

1336599.126346

  

0.2245000000e15

  

0.2979900000e11

  

4715700.713/Pi^.5

 (1)
> 

y(x) = rho*c((1-(x/a)^2)^(1/2)-(1-(R/a)^2)^(1/2))^2/(3*(1-(R/a)^2)^(1/2)-(1-(x/a)^2)^(1/2))

y(x) = 0.1993516000e36/(3*(1-0.8033593953e-1*Pi^1.0)^(1/2)-(1-0.4496840993e-13*x^2*Pi^1.0)^(1/2))

 (2)
> 

``


 

Download y(x).mw

how to a convergent solution...

umar khan 30
differential-equation numeric convergence
December 04 2016
3 20

I wrote an equation and intended to iterate P(r) till that value of r when P(r) becomes 0.what is the value of r for which P(r)=0, and also  obtained its convergent decreasing graph which show convergence of P(r) to 0.
 

> 

restart
> 

NULL
> 

G := 6.6743*10^(-8);

0.6674300000e-7

  

0.2997924580e11

  

0.7321400000e36

 (1)
> 

``
> 

sys2 := diff(P(r), r) = -G*(epsilon+P(r))*((8.98*10^14*(1/3))*Pi*r^3+4*Pi*r^3*P(r)/c^2)/(c^2*(r^2-(2*G*r*(8.98*10^14*(1/3))*Pi*(r^3))/c^2)), P(0.1e-9) = 8.5561*10^34

diff(P(r), r) = -0.7426160269e-28*(0.7321400000e36+P(r))*(0.2993333333e15*Pi*r^3+0.4450600224e-20*Pi*r^3*P(r))/(r^2-0.4445794614e-13*r^4*Pi), P(0.1e-9) = 0.8556100000e35

 (2)
> 

``
> 

``


 

Download decreasing_graph.mw

how do i solve the boundary conditions...

umar khan 30 Maple
differential-equation numeric bvp
December 01 2016
1 3


 

> 

refresh

refresh

 (1)
> 

G := 6.6743*10^(-8); 1; c := 2.99792458*10^10; 1; pi := 3.143; 1; rho := 5.3808*10^14

0.6674300000e-7

  

0.2997924580e11

  

3.143

  

0.5380800000e15

 (2)
> 

diff(P(r), r) = -G*(rho*c^2+P(r))*((4*pi*r^3*(1/3))*rho+4*Pi*r^3*P(r)/c^2)/(c^2*(r^2-2*G*r*(4*pi*r^3*(1/3))*rho/c^2)), diff(v(r), r) = 1.485232054*10^(-28)*((4*pi*r^3*(1/3))*rho+4.450600224*10^(-21)*Pi*r^3*P(r))/(r^2-1.485232054*10^(-28)*r*(4*pi*r^3*(1/3))*rho)

diff(P(r), r) = -0.7426160269e-28*(0.4836021866e36+P(r))*(0.2254913920e16*r^3+0.4450600224e-20*Pi*r^3*P(r))/(r^2-0.3349070432e-12*r^4), diff(v(r), r) = 0.1485232054e-27*(0.2254913920e16*r^3+0.4450600224e-20*Pi*r^3*P(r))/(r^2-0.3349070432e-12*r^4)

 (3)
> 

condition; -1; P(0) = 0, v(1014030) = -.4283

P(0) = 0, v(1014030) = -.4283

 (4)
> 

``


 

Download maple_soft.mw

I found the solution of P(r) at P(0)=0, but could obtain the result of v(r) at v(1014030)=-0.4283, v(r) may have a graph such that i can goes from -0.4283 to 0.

how to solve the challenging non linear ...

umar khan 30 Maple 18
ode dsolve numeric
November 29 2016
2 7

G := 6.6743*10^(-8);

a := 1.9501*10^24;

b := .3306;

c := 2.99792458*10^10;

d := 2.035;

pi := 3.143;

eps := 3.8220*10^35;

g(r) = 1-s(r)/0.06123;

j(r) = e^(-(1/2)*w(r))*(1-2*G*v(r)/(r*c^2))^.5

sys := diff(v(r), r) = 4*pi*r^2*eps/c^2, ics=v(0)=0

diff(u(r), r) = -G*(eps+u(r))*(v(r)+4*Pi*r^3*u(r)/c^2)/(c^2*(r^2-2*G*r*v(r)/c^2)),u(0)=1.3668*10^34

diff(w(r), r) = 1.485232054*10^(-28)*(v(r)+4.450600224*10^(-21)*pi*r^3*u(r))/(r^2-2*G*r*v(r)/c^2), conditions: w(0)=0,iterate it to find w(688240)=-2.05684, it solve must satistfy the both conditions.

diff(r^4*j(r)*(diff(g(r), r)), r)+4*r^3*g(r)*(diff(j(r), r)) = 0, conditions dg(r)/dr =0  at r=0, g(688240) =0.87214

diff(J(r), r) = (8*pi*(1/3))*(eps/c^2+u(r)/c^2)*(g(r)*j(r).(r^4))/(1-2*G*v(r)/(r*c^2)) condition J(0)=0.

1 2 3 Page 3 of 3