MaplePrimes - Questions and Posts tagged with derivative

How to solve the partial derivative at a specified point

ytyyutianyun — Tue, 17 Apr 2012 12:52:50 Z

How to solve the partial derivative at a specified point

The latex code is

f(x,y)=x+(y-1)\arcsin\sqrt{\frac{\,x}{y}}

f''_{xx}(x,1)

Derivative function problems

xjtlu2007 — Sat, 31 Mar 2012 00:08:25 Z

I'm now using Maple 15 to get derivative funtions in a function with multiple parameters. So I want to find out the derivative w.r.t just one parameter. In the forum, I found out one way to solve this issue.

In order to prove the correctness of the function D[3](m,n,p,r,x), I firstly use a very simple program to test it.

In the Engineering PoA-Example.mw file, I've used a simple function called testFor with 5 parameters to generate a mathematical...

derivative of an equation with rootsof in it, errors to "floats not handled"

kutscher — Tue, 28 Feb 2012 18:31:34 Z

Hi,

I'd like to take the second derivative of the following function (see below), but I keep ending up with an

Error, (in content/polynom) general case of floats not handled

The range of the equation that I want to look at is from 0 to 1 and I know that it "blows up" around 0.09 for EQ1 but not EQ2.

The commands that I've tried are diff(%,FIO2) and Diff(%,FIO2). I'm probably missing something obvious, so hopefully someone can tell me...

Differentiation formula for parametric equations sequential

amrramadaneg — Fri, 17 Feb 2012 09:21:34 Z

Hi, I have the following

for i from 1 to 100 do x[i]:=cos(θ[i]); y[i]:=sin(θ[i]) end do;

Now I want to find the first and second derivatives for x[i] and y[i] which are

for i from 1 to 100 do x1dot[i]:=-sin(θ[i]); y1dot[i]:=cos(θ[i]);

...

Finding maximum and minimum values

Red Horse — Sun, 12 Feb 2012 00:33:30 Z

I have a region x^2 + y^2 <= 1 and y>=0. It's temperature function is f(x,y) x^2 - 2y^2 + x + y. How do I find the max and min temperatures on the lower boundary y=0?

I took the derivatives with respect to x and with respect to y such that:

fx:=diff(f(x,y),x);

fy:=diff(f(x,y),x);

Then I used fsolve({fx=0, fy=0},{x,y}) which game me (-0.5, 0.25)

Is there really only one critical point on that lower bound...

differentiate functions

thuan huynh — Wed, 01 Feb 2012 19:42:27 Z

create the function f(x)=(x²,x=<0), (2x, 0<x<1), (2sin(Pi.x/2),x>=1). how do you find derivative in one command and integrate f(s)ds from -1 to 2.

Multivariable function in matrix form

serena88 — Tue, 24 Jan 2012 22:13:10 Z

Hi,

I would like to discribe the following function.

w(ξ,s):=N(s)*w(ξ)

N(s) and w(ξ) are both matrix. I have defined N(s) but will be searching for w(ξ) much later in the process. Why does it not allow me to define a partial derivative of w(ξ) now for future use? d/dξ(w(ξ)) is not allowed. it says that "Error, invalid input: w uses a 2nd argument, s, which is missing". But my w(ξ) only depends on the variable ξ.

2nd question, how do i tell maple that x...

Fundiff with anticommuting functions

Higgsino — Wed, 11 Jan 2012 13:47:47 Z

Hi everybody,

during testing the physics package I tried the following example

with(Physics):

Setup(anticommutativeprefix = {Q});

G:= Intc(Q1(x),Q2(y),x,y);

Fundiff(G,Q2(u));

The output of the last command seems to be wrong. The Maple Help does not say anything about functional derivatives with respect to anti commuting functions.

Is there a possibility to perform such functional derivatives with respect to anti commuting functions in Maple?...

Collecting similar derivative terms of the variables

rpd25 — Wed, 04 Jan 2012 04:37:39 Z

Hi,

I need help of your expertize in solving the following queries:

I would start with a sample equation:

Eq1 = u_{xxxx} + u_{xxyy} - v_{xxxy} - v_{xyyy} 
where u_{xxxy} represents 4th order pde of u i.e. d^4/(dx^3 dy).

I get a equation similar to Eq1 (but quite complicated) on solving the 
equilibrium equations. I would like to collect the similar derivatives
for variable u and v together like

Eq2 = d^2/d x^2 ( u_{xx} + u_{yy} ) - d^2/dx dy ( v_{xx} + v_{yy} )

series approximation

icegood — Mon, 05 Dec 2011 19:35:29 Z

In next procedure i calculated 1st derivative of H in y=0 via series approximation. And i see that some terms of series are missed. If i would raise second parameter to cnt+20 for FuncToSeries in GetLimitsArray it becomes better. But why it's not OK with even cnt+8? series_test.mw

Computing Implicit Derivatives

Joe Riel — Tue, 22 Nov 2011 16:46:27 Z

Over the weekend I was attempting to estimate the tension change in a bicycle spoke due to an applied load. After various simplifications and approximations, the problem was reduced to the following.

Given a constraint, F(x,y) = 0, and functions G(x,y) and H(x,y), find dG/dH at a particular point, here (0,0).

The constraint, F, was sufficiently complicated that solving for either variable was not feasible, so implicit differentiation seemed the best...

Please help me optimize code

icegood — Sun, 06 Nov 2011 13:18:13 Z

main.mw

Please, start attach from beginning till that place where

Identify a Tangent Line

rustiri — Mon, 31 Oct 2011 15:43:53 Z

How to solve this problem in maple?
Decide which of three lines given are tangent to the graph of f(x) at given points.
The function to define is f(x)=2x^3-4x^2+3x-5
The possible tangent lines are:
y = x - 5
y = 2x - 5
y = 3x - 5

1. What is/are the zero(es) for this function? In other words, what is the solution for f(x)= 0

2. What axes values (x- and y- ranges) are appropriate for this graph?

3. When plotting each linear function with f(x...

Find total derivative of y=(a-3)/(b+3)

jmaried133 — Mon, 24 Oct 2011 02:28:45 Z

I'm very new to this... I need to find the total derivative of y=(a-3)/(b+3) given that a=r*t and b=s*t

How do I make Maple do this bit of calculus?

Edo Karura — Sat, 22 Oct 2011 03:37:40 Z

Pretty basic stuff here...

How can I get Maple to do this - go from Step (1) directly to Step (5 or beyond). I'm guessing that all I have to do is figure out how to enter the derivative dy/dx into the document and then Solve for whatever variable I like.

Thanks in advance!