Advanced Search

Ahmed111

140 Reputation

5 Badges

7 years, 126 days
Contact Ahmed111

MaplePrimes Activity


These are questions asked by Ahmed111

Error, (in Optimization:-NLPSolve)...

Ahmed111 140 Maple 2022
optimization
November 29 2022
3 3

I try to find the value of the highest peak by using Optimization. But Maple returns an error with the comment "Error, (in Optimization:-NLPSolve) abs is not differentiable at non-real arguments". How to remove it?

plot.mw

How can we draw the pot function?...

Ahmed111 140 Maple 2022
plotting incomplete-question
November 24 2022
1 2

How can we draw the pot function the same as in the attached figure (namely 'pot.png')? The values of V(x) may not be the same.

pot.mw

Error in dchange...

Ahmed111 140 Maple 2022
pde differential-equations dchange
November 16 2022
1 2

dchange gives the error when I try to convert pde into ode. Why?

> 

restarts
> 

with(PDEtools)
> 

pde1 := diff(u(x, t), t)-(diff(u(x, t), `$`(x, 2), t))+3*u(x, t)^2*(diff(u(x, t), x))-2*(diff(u(x, t), x))*(diff(u(x, t), `$`(x, 2)))-u(x, t)*(diff(u(x, t), `$`(x, 3))) = 0

diff(u(x, t), t)-(diff(diff(diff(u(x, t), t), x), x))+3*u(x, t)^2*(diff(u(x, t), x))-2*(diff(u(x, t), x))*(diff(diff(u(x, t), x), x))-u(x, t)*(diff(diff(diff(u(x, t), x), x), x)) = 0

 (1)
> 

trans1 := {seq(var[i] = tau[i], i = 2), FN = Y(zz), var[1] = (zz-(sum(lambda[i]*tau[i], i = 2)))/lambda[1]}

{FN = Y(zz), var[1] = (-lambda[2]*tau[2]+zz)/lambda[1], var[2] = tau[2]}

 (2)
> 

ode1 := dchange(trans1, pde, [Y(zz), zz, seq(tau[i], i = 2)])

Error, (in dchange/info) the number of new and old independent variables must be the same. Found {zz, tau[2]} as new, while {FN, var[1], var[2]} as old

  
> 

op(lhs(pde1))

diff(u(x, t), t), -(diff(diff(diff(u(x, t), t), x), x)), 3*u(x, t)^2*(diff(u(x, t), x)), -2*(diff(u(x, t), x))*(diff(diff(u(x, t), x), x)), -u(x, t)*(diff(diff(diff(u(x, t), x), x), x))

 (3)
> 

 

Download P_O.mw

How can we get the single possible solut...

Ahmed111 140 Maple 2020
ode dsolve differential-equations
October 06 2022
4 2

I solved the differential equation using 'dsolve' and Maple returns it with fiver possible solutions. How can we get the single possible solution for w(x) if we assume c, g (constants) are positive? Also, can we convert JacobiSN() to a simple trigonometric or algebraic function?

> 

restart
> 

with(DEtools)
> 

``
> 

q := (1/2)*(diff(w(x), x))^2+(1/8)*w(x)^4-(1/2)*c*w(x)^2-g = 0

(1/2)*(diff(w(x), x))^2+(1/8)*w(x)^4-(1/2)*c*w(x)^2-g = 0

 (1)
> 

dsolve((1/2)*(diff(w(x), x))^2+(1/8)*w(x)^4-(1/2)*c*w(x)^2-g = 0, {w(x)})

w(x) = (2*c+2*(c^2+2*g)^(1/2))^(1/2), w(x) = (-2*(c^2+2*g)^(1/2)+2*c)^(1/2), w(x) = -(2*c+2*(c^2+2*g)^(1/2))^(1/2), w(x) = -(-2*(c^2+2*g)^(1/2)+2*c)^(1/2), w(x) = 2*JacobiSN((1/2)*(-2*c+2*(c^2+2*g)^(1/2))^(1/2)*x+_C1, ((c*(c^2+2*g)^(1/2)-c^2-g)*g)^(1/2)/(c*(c^2+2*g)^(1/2)-c^2-g))*g/(g*(-c+(c^2+2*g)^(1/2)))^(1/2)

 (2)
> 

``

``

Download solve.mw

How to linearize equation?...

Ahmed111 140 Maple 18
linearize
September 22 2022
2 12

How to linearize eq (6) by neglecting all higher order terms i.e., epsilon[1]^2, epsilon[2]^2, epsilon[1]*epsilon[2]... etc? How to do it in maple?

Calculation.mw

1 2 3 4 5 6 7 Page 3 of 9