sunit

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These are questions asked by sunit

Hi,

It might be really trivial, but I am struggling in the algebraic manipulation of the argument of the exponential function. As an example, I want to substitute 

I*T[0]*(omega1-2*omega2) = I*omega2*T[0]-I*si*T[2]

in the expression of

exp(-I*T[0]*(omega1-2*omega2)).

However, I am only able to do so by subs command and also by exactly copying the argument in the following manner.

subs(-I*T[0]*(omega1-2*omega2) = I*omega2*T[0]-I*si*T[2], exp(-I*T[0]*(omega1-2*omega2)))

The issue is I have expressions like this all over in the main problem, and I have to copy-paste such expressions for the substitution. So I am wondering if there is a more efficient way to tackle this problem. 

Thanks in Advance,

Regards

Hi,

It might be a really silly question, but I am wondering is it possible to simplify expression like this

a^2+b^2+2*a*b+c^2. Just by looking it we know that we can write it in the form of (a+b)^2+c^2. This is the basic exmaple I come up with. I have very lengthy expressions in maple, which can be factorize like this, but factor command will not work as it will try to factorize entire expression. So I am wondering is it doable in maple or I have to do it manually by collecting terms and check whether they can be factorize or not.

Thanks in Advance.

With Regards

sunit

Hi,

This might be a very silly question but it is troubling me a little bit and that's why I need to post it. During the combination of symbolic and numerical comutation this '1.0' is appearing as a coefficient for the variables whose coeffecient is just '1'. It's quite annoying as sometimes if I have to collect coefficient of a variable for an example exp(I*omega*t) then I have to write exp(1.I*omega*t), so chances of making mistake is higher. Please find the attached worksheet for this. In eq(4), you can easily see that for x[3](t) and x[1](t) this '1.0' appears in front of the variables.

I really appreciate  if someone can help me out of this.

With Regards

Sunitquestion.mw
 

restart

with(LinearAlgebra):

par := {a = 2.5, alpha = 2, k_r = .5, k_rc = .2, k_rq = .2, kappa = 0.1e-2, mu_k = .35, mu_s = .44, omega = .766620580157922, sigma_0 = 110, sigma_1 = 1.37, sigma_2 = 0.823e-1, x_s3 = -1.04003626422324936017819852700633621040584050594846801927800, zeta = 0.904504977553123318334601762827181333680096702957228781770315e-1}:

f := proc (v_r) options operator, arrow; mu_k+(mu_s-mu_k)*exp(-a*v_r) end proc:

NULL

g_exp1 := taylor(1/f(v_rv+x21), x21 = 0, 4):

for k to 4 do g_coeff[k] := taylor(subs(v_r = v_rv, coeff(g_exp1, x21, k-1)), epsilon = 0, 3) end do:

g0 := eval(subs(par, coeff(g_coeff[1], epsilon, 0))):

g1 := eval(subs(par, coeff(g_coeff[2], epsilon, 0))):

g2 := eval(subs(par, coeff(g_coeff[3], epsilon, 0))):

g3 := eval(subs(par, coeff(g_coeff[4], epsilon, 0))):

NULL

``

eq[1] := subs(par, diff(x[1](t), t)-x[2](t)):

eq[2] := subs(par, diff(x[2](t), t)+2*zeta*x[2](t)+x[1](t)+k_r*(x[1](t)-x[3](t))+2*kappa*(x[2](t)-x[4](t))+k_rq*(x[1](t)-x[3](t))^2+k_rc*(x[1](t)-x[3](t))^3)

diff(x[2](t), t)+.1829009955*x[2](t)+1.5*x[1](t)-.5*x[3](t)-0.2e-2*x[4](t)+.2*(x[1](t)-x[3](t))^2+.2*(x[1](t)-x[3](t))^3

(1)

eq[3] := subs(par, diff(x[3](t), t)-x[4](t))

diff(x[3](t), t)-x[4](t)

(2)

eq[4] := subs(par, diff(x[4](t), t)+2*kappa*alpha*(x[4](t)-x[2](t))+k_r*alpha*(x[3](t)-x[1](t))-k_rq*alpha*(x[3](t)-x[1](t))^2+k_rc*alpha*(x[3](t)-x[1](t))^3+alpha*(sigma_0*x[5](t)+sigma_1*v_r*(1-sigma_0*x[5](t)*(g_0+g_1*x[4](t)+g_2*x[4](t)^2+g_3*x[4](t)^3))+sigma_2*v_r))

diff(x[4](t), t)+0.4e-2*x[4](t)-0.4e-2*x[2](t)+1.0*x[3](t)-1.0*x[1](t)-.4*(x[3](t)-x[1](t))^2+.4*(x[3](t)-x[1](t))^3+220*x[5](t)+2.74*v_r*(1-110*x[5](t)*(g_0+g_1*x[4](t)+g_2*x[4](t)^2+g_3*x[4](t)^3))+.1646*v_r

(3)

eq[5] := subs(par, diff(x[5](t), t)-v_r*(1-sigma_0*x[5](t)*(g_0+g_1*x[4](t)+g_2*x[4](t)^2+g_3*x[4](t)^3)))

diff(x[5](t), t)-v_r*(1-110*x[5](t)*(g_0+g_1*x[4](t)+g_2*x[4](t)^2+g_3*x[4](t)^3))

(4)

``


 

Download question.mw

 

Hi Guys,

I am trying to intgrate a function involving hyperbolic functions in a range of 0 to 1 and it is giving me very large value of 10^94. However, on doing integration terms terms i can see that some large terms involving 10^191 cancel out with each other and I can have a fnite value of this integration. It would be really helpful if someone can help me out why it is happening with int function and how can I solve this case involving hyperbolic function. For reference maple file is attached. Thanks in advance and much appreciated.

With Regards

Sunit

question.mw

Hi Guys,

I need help regarding simplifying definite integrals. I have following expression

2*s^2*(int(Phi[1, 1](x, T[2])*(diff(Y1(x), x, x)), x = 0 .. x1))+int(Phi[1, 1](x, T[2])*(diff(Y1(x), x, x, x, x)), x = 0 .. x1)-omega_y^2*(int(Y1(x)*Phi[1, 1](x, T[2]), x = 0 .. x1))

As we can notice the limit for each integral is same, so I should be able to take these integral limit outside. I am trying to use collect and simplify, but both of these command are not working. It would be really helpful for me if I can get the solution for it.

Please find the attached example sheet also.example.mw

With Regards

Sunit

 

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