FormatB

25 Reputation

3 Badges

7 years, 118 days

MaplePrimes Activity


These are questions asked by FormatB

Hello Everyone,

First of all I want to thank you to pay attention to my post.

For some reasons I want to know when does the root of my solution is equal to 0 isolating α, which yields the following equation
 

(6*alpha^4*l^2-7*alpha^3*l^2+6*alpha^3*l+2*alpha^2*l^2-6*alpha^2*l+alpha*l+3*alpha-2*sqrt(alpha^3*l^2*(alpha*l-l+1)*(9*alpha^4*l-13*alpha^3*l+9*alpha^3+6*alpha^2*l-12*alpha^2-alpha*l+6*alpha-1))-1)*(-1+2*alpha)/(alpha^2*l-3*alpha+1)^2 = 0
``

  1/2, -1/l, (1/8)*(3*l+(9*l^2-16*l)^(1/2))/l, -(1/8)*(-3*l+(9*l^2-16*l)^(1/2))/l``

``

NULL

 

NULL

``

 

 

When I substitute 1/2 it verifies the equation, but when I substitute other solutions my equation is not verified. For instance substituting "α=-1/l" I get something different from 0 as you can see

``

``

(6*alpha^4*l^2-7*alpha^3*l^2+6*alpha^3*l+2*alpha^2*l^2-6*alpha^2*l+alpha*l+3*alpha-2*sqrt(alpha^3*l^2*(alpha*l-l+1)*(9*alpha^4*l-13*alpha^3*l+9*alpha^3+6*alpha^2*l-12*alpha^2-alpha*l+6*alpha-1))-1)*(2*alpha-1)/(alpha^2*l-3*alpha+1)^2
"(->)"(-2/l-2*(1/l^2)^(1/2))*(-2/l-1)/(4/l+1)^2"(=)"2*((1/l^2)^(1/2)*l+1)*(2+l)/(4+l)^2

``

My question is what are these "solutions" if they are not solutions ?

I attach the file in case you would take a look at it

Download Maple_question2.mw

Hello everyone,

First I want to thank you for paying attention to my post.

I'm trying to determine the maximum of the following function:

Maple Code:

(1/4)*(-1/4+alpha*(-1+b)*e^2+((1-b)*alpha+(1/4)*b)*e)^2/((-1+e)^2*(b*e-1)*alpha*e*(-1+b))(1/4)*(-1/4+alpha*(-1+b)*e^2+((1-b)*alpha+(1/4)*b)*e)^2/((-1+e)^2*(b*e-1)*alpha*e*(-1+b))

e is my variable and I want to study it in [0,1[. I have a several parameters restriction like b in [0,1[ and alpha>1.

When I value this function for specific values (b=0.1, alpha=4 for instance) I get the equation and its associated graphic representation:

Maple Code:

-0.6944444445e-1*(-1/4-3.6*e^2+3.625000000*e)^2/((-1+e)^2*(.1*e-1)*e)

 

 

I'm only interested in the domain where e is betweeen 0 and 1. I clearly on the graph see that there is a maximum and when 1) I compute roots of the expression I get 2) following solutions:

1)

2) 

    0.9324708634, 0.07447358108, 0.6965691592, 1.345632810, 

      -0.07419084270.

Here: 0.6965691592 corresponds to the maximum I'm looking for.

So now when I try to get a generalization of this function according to my parameters and when I compute the first derivative with respect to e

1)

 

2) 

3)...

the last is very big so I do not write it here.

To sum-up: I see that the solution I'm looking for exists but when it comes to use parameters I cannot define correct roots.

Page 1 of 1