Items tagged with newton

Basically what I'm trying to do is use Newton's method to find the root of f(x)=sqrt(x)+ln(0.1x) starting at x0=5 within a tolerance of 0.001.


f := proc (x) options operator, arrow; sqrt(x)+ln(.1*x) end proc

> xk := 1.0;
print(`output redirected...`); # input placeholder
> for k to 6 do xk1 := xk-f(xk)/(D(f))(xk); xk := xk1 end do;


When I do that, Maple barfs out pages of nonsense when I'm looking for it to give numerical values. It seemed to work fine with a different function, so maybe that's part of the problem? But I need to do it with the function I asked about.

how i can find order of convergence of newton method by expanding taylor series?? plz send me code???


Dear All,

I am going to solve the following systems of ODEs but get the error: Newton iteration is not converging.
Could you please share your idea with me. In the case of AA=-0.2,0,0.2,0.4,...; I could get the solution.
Thank you in advance.

Pr := 2; Le := 2; nn := 2; Nb := .1; Nt := .1; QQ := .1; SS := .1; BB := .1; CC := .1; Ec := .1; MM := .2;AA:=-0.4;

Eq1 := diff(f(eta), `$`(eta, 3))+f(eta).(diff(f(eta), `$`(eta, 2)))-2.*nn/(nn+1).((diff(f(eta), eta))^2)-MM.(diff(f(eta), eta)) = 0; Eq2 := 1/Pr.(diff(theta(eta), `$`(eta, 2)))+f(eta).(diff(theta(eta), eta))-4.*nn/(nn+1).(diff(f(eta), eta)).theta(eta)+Nb.(diff(theta(eta), eta)).(diff(h(eta), eta))+Nt.((diff(theta(eta), eta))^2)+Ec.((diff(f(eta), `$`(eta, 2)))^2)-QQ.theta(eta) = 0;
Eq3 := diff(h(eta), `$`(eta, 2))+Le.f(eta).(diff(h(eta), eta))+Nt/Nb.(diff(theta(eta), `$`(eta, 2))) = 0;

bcs := f(0) = SS, (D(f))(0) = 1+AA.((D@@2)(f))(0), theta(0) = 1+BB.(D(theta))(0), phi(0) = 1+CC.(D(phi))(0), (D(f))(etainf) = 0, theta(etainf) = 0, phi(etainf) = 0

Error, (in dsolve/numeric/ComputeSolution) Newton iteration is not converging

Hello Everybody,

I was trying to apply the Newton-Raphon method("Newton" in maple) for the following problem to obtain the constants (c1...cM) without success.

eq[1] := -0.0139687 c[2] - 0.0132951 c[1] = 0
eq[2] := 24806.4 c[2] - 0.0139687 c[1] = 0

If anybody has experience with it or knows how to use it I would really appreciate your help.


Just to introduce the previous steps of calculations leading to the problem:To calculate the critical buckling force N and the shape of a rectangular uniformly loaded plate the governing diff. equation is the following


For the follwing solution of a boundary value problem(Boundary conditions:clamped-clamped: w(x=0,x=a)=0 & w'(x=0,x=a)=0) I applied the Ritz method:


Thus the Potential Energy P is:


 deriving P to each constant c and setting them =0 leads to:

eq[1] := -0.0139687 c[2] + 2067.20 c[1] - 4.93480 N c[1] = 0
eq[2] := 33075.2 c[2] - 0.0139687 c[1] - 19.7392 N c[2] = 0

After calculating N=418,902  and feeding eq1 and eq 2,the follwing equations if two terms are considered:

eq[1] := -0.0139687 c[2] - 0.0132951 c[1] = 0
eq[2] := 24806.4 c[2] - 0.0139687 c[1] = 0

Everything I tried resulted in any c1 = c2 = 0 which is not  realistic. Maybe I made a mistake earlier.

Thanks a lot in advance.


let γ be the root 

i have to apply taylor series on f(x) and then do some substitution like (helped by a member of Mapleprime)

taylor(f(x), x = gamma, 8);
f(x[n]) := subs([x-gamma = e[n], f(gamma) = 0, seq(((D@@k)(f))(gamma) = factorial(k)*c[k]*(D(f))(gamma), k = 1 .. 1000)], %)

then find the derivative of result from above output

i do

b := diff((x[n]), e[n])

basically i have to find the value of newton method which is


here we substitute xn=γ and D(f)(xn)=b

and then want to apply f on yn

there are to problem which i face 

1  f(xn)/D(f)(xn) is not in simplified form i-e O(e[n]^8) and O(e[n]^7) is appeared in numerator and denominator respectively. how we get the simplified result.

2 wht step should i do to find f(yn)

plx help me to do this 

thanx in advance

I would like to use Newton's Method (the multivariate one) in order to solve a system of equations. From what I understand, fsolve is essentially MAPLE's version of the multivariate Newton's Method. Is there a way to do the multivariate Newton's method any other way, other than fsolve? Also, is there a way to specify our own initial guess and tolerance for the Newton's Method and to get other details such as the number of iterations?

Hi all!


I do a small calculation and get a system of 6
nonlinear equations.
And "n" is the degree of the equation is float.

Here are the calculations that lead to the system.


 M_1:=piecewise((z<l), l-z, 0):
 M_2:=piecewise((z<2*l), 2*l-z, 0):
 M_3:=piecewise((z<3*l), 3*l-z, 0):
 M_4:=piecewise((z<4*l), 4*l-z, 0):
 M_5:=piecewise((z<5*l), 5*l-z, 0):
 for i from 2 to N do
 end do:
 So,my system:



I want to ask advice on how to solve the system.
I wanted to use Newton's method, but I don't know the initial values X_1..X_6.

Tried to set the values X_1..X_6 and to minimize the functional

with the help with(DirectSearch):
But I don't know what to do next

Please, advise me how to solve the system! I would be grateful for examples!


Hi, I am using Maple 18 and struggling with plotting Newton's Method.

I am wanting use the function f(x)=x^3 +cx + 1 where c is a parameter and uses 100 parameter values between -2 and 0, with 100 iterations of each parameter.

Any help would be brilliant.

Thanks in advance,


Hello, I'd like to use Maple to use Newton's Method in an interval to find multiple roots of 4xcos(3x)+(x-2)^2-2=0. What I have so far is:

f := 4*x*cos(3*x)+(x-2)^2-2:


Other than trying out different initial guesses is there a way to do this?

I can get the function to iterate as a recursive function by just reevaluating the x := evalf(x-(f1*j-i*g1)/(h*k-i*j), 25); y := evalf(y-(h*g1-f1*j)/(h*k-i*j), 25) portion of the function below but im trying beneath it to assign it as newt2d so that i can iterate it as newtons method in two variables like (newt2d@@10) and I can't seem to figure out what im doing wrong. Thanks for any help you can provide!

f := proc (x, y) options operator, arrow; x+y-cos(x)+sin(y-1) end proc; f1 := f(x, y)

(x, y) -> x + y - cos(x) + sin(y - 1)
x + y - cos(x) + sin(y - 1)

> g := proc (x, y) options operator, arrow; x^4+y^4-2*x*y end proc; g1 := g(x, y);

(x, y) -> x + y - 2 x y
x + y - 2 x y

> dh := D[1](f); h := dh(x, y);

(x, y) -> 1 + sin(x)
1 + sin(x)

> di := D[2](f); i := di(x, y);

(x, y) -> 1 + cos(y - 1)
1 + cos(y - 1)

> dj := D[1](g); j := dj(x, y);

(x, y) -> 4 x - 2 y
4 x - 2 y

> dk := D[2](g); k := dk(x, y);

(x, y) -> 4 y - 2 x
4 y - 2 x

x := .3; y := .8


> x := evalf(x-(f1*j-i*g1)/(h*k-i*j), 25); y := evalf(y-(h*g1-f1*j)/(h*k-i*j), 25);


> newt2d(.3, .8);

0.2577789764, 0.8333916830

> (newt2d@@5)(.3, .8);

Error, (in @@) invalid arguments



Can anyone help me with this error in Maple while using prcNewton to find local extrema: 


> prcNewton := proc () 
local ftn, strpt, epsilon, maxlps, i, xn, dftn; 
if 4 < nargs then 
elif nargs < 2 then end if; 
if nargs = 2 then 
epsilon := 1/10000000; 
maxlps := 1000 
elif nargs = 3 then 

Use Newton's Method to find a local extrema for f(x)=sin(x^2)+x

with start point x=(1,0)

take derivative of f(x) then apply Newton's Method


My teacher started us off with this but I can't seem to get it to work the way she did, any help would be appreciated!


prcNewton:=proc( ) 

  local ftn,strpt,epsilon,maxlps,i,xn,dftn; 

  if nargs>4 then     

This thread stimulated me into playing with a few ideas,

I pieced together this little newton-raphson procedure...

> newton := proc( f, # the function x0 # the initial guess n, # step count limit tol # error tolerance)

local x, g, k;

g := D(f); # the derivative f’(x)

x[0] := evalf(x0); # initialize the iteration

for k from 1 to n do # loop for newton’s iteration

# Newton’s iteration formula

I have been working with Newton-Raphson fractals for some time.  Like others it was necessary to deal with the "black areas" many times, so I performed some additional analysis and present some of these results here.  This will allow others to stop coloring these areas black and allow visualization of the structure inside these areas.  It will also help demonstrate...

Use Newton’s Method to approximate the indicated root of the equation to correct six decimal places.


The root of 2.2x5 – 4.4x3 + 1.3x2-0.9x-4.0=0 in the interval [-2, -1].


The rest of the assignment states : "

Start by plotting the function in
Maple to get a reasonably good initial approximation. You may use a
“while” loop, but do not use existing Maple commands for Newton’s
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