In mathematics, the derivative of a function of a real variable measures the sensitivity to change of the function value (output value) with respect to a change in its argument (input value). Derivatives are a fundamental tool of calculus. For example, the derivative of the position of a moving object with respect to time is the object's velocity: this measures how quickly the position of the object changes when time advances.
The derivative of a function of a single variable at a chosen input value, when it exists, is the slope of the tangent line to the graph of the function at that point. The tangent line is the best linear approximation of the function near that input value. For this reason, the derivative is often described as the "instantaneous rate of change", the ratio of the instantaneous change in the dependent variable to that of the independent variable.
Derivatives can be generalized to functions of several real variables. In this generalization, the derivative is reinterpreted as a linear transformation whose graph is (after an appropriate translation) the best linear approximation to the graph of the original function. The Jacobian matrix is the matrix that represents this linear transformation with respect to the basis given by the choice of independent and dependent variables. It can be calculated in terms of the partial derivatives with respect to the independent variables. For a real-valued function of several variables, the Jacobian matrix reduces to the gradient vector.
The process of finding a derivative is called differentiation. The reverse process is called antidifferentiation. The fundamental theorem of calculus relates antidifferentiation with integration. Differentiation and integration constitute the two fundamental operations in single-variable calculus.
The answer is E. I was initially very confused as to why the answer was not A but realized that the graph was velocity vs position (rather than velocity vs time) which means I can't simply take the derivative of the given graph.
One thing I tried was writing out the equation first(c being a...
What should I do when the f(x, y) function's second derivatives or Δ=AC-B² is zero? When the function is f(x) then we can differentiate it until it won't be a zero, but if z = some x and y then can I just continue this process to find what max and min (extremes) it has?
What I've done is...
Hi, I'm trying to calculate my own physics problem but didn't get it something.
When I'm trying to calculate the impulse of the object when it's hit by F=10N force in the smallest possible time, then should I write:
dP/dt = Fnet => dP = Fnet*dt ?
Another question: In general, if I calculate...
Problem statement : I draw the problem statement above. I hope I am correct in inferring that the bowl is hemispherical.
Attempt : I could not attempt to the solve the problem. We are given that the rate of change (decrease) in volume is proportional to the surface area ...
Hi, if the force is the derivative of potential energy, does it mean that the force is equal to mg and with a constant gravity, it will be the same at any height?
But in real life, F (or mg) would be different on the Earth's surface and 400 km above it (~8 m/s^2).
So, this formula is used to...
I originally thought you’d have to use the chain rule to get h’, as in: f’(g(x))*g’(x). Plugging in 1 for x, I got an answer of 10. An online solution, however, said that you only had to get f(g(1)), which was f(-1), then look up f’(-1) in the table. Both approaches seem logical to me, but they...
in class we derived the following relationship:
$$\frac{1}{V}\frac{dV}{dt}= \nabla \cdot \vec{v}$$
This was derived though the analysis of linear deformation for a fluid-volume, where:
$$dV = dV_x +dV_y + dV_z$$
I understood the derived relation as: 1/V * (derivative wrt time) = div (velocity)...
Hello,
There is a thread related to this question however it was marked correct but doesn't look correct to me?
https://www.physicsforums.com/threads/step-change-in-a-proportional-plus-integral-controller.961180/
I think I have it but it is quite different to other answers I have seen?
I...
We have 2 forces affecting the rope: 1. Gravitational force of the body ##=mg## and 2. Force of air = Force of drag= ##F_{AIR}##.
The length of the rope is shortening with the velocity ##v_k##.
So to figure out the angle ##\theta## I wrote:
##R##= force of rope
##R_x = F_{AIR}##
##R_y = mg##...
Given
\begin{equation}
\begin{split}
\int_{y-\epsilon}^{y+\epsilon} \delta^{(2)}(x-y) f(x) dx &= f^{(2)}(y)
\end{split}
\end{equation}
where ##\epsilon > 0##
Is the following also true as ##\epsilon \rightarrow 0##
\begin{equation}
\begin{split}
\int_{y-\epsilon}^{y+\epsilon}...
Hi everyone.
I am studying Chebyshev Polynomials to solve some differential equations. I found in the literature that if you have a function being expanded in Chebyshev polynomials such as
$$
u(x)=\sum_n a_n T_n(x),
$$
then you can also expand its derivatives as
$$
\frac{d^q u}{dx^q}=\sum_n...
I was solving a problem for my quantum mechanics homework, and was therefore browsing in the internet for further information. Then I stumbled upon this here:
R is the rotation operator, δφ an infinitesimal angle and Ψ is the wave function.
I know that it is able to rotate a curve, vector...
Hello everyone, I'm stuck doing this problem, I've tackled the partial derivative but i can't figure out the derive for x component part, i solved the partial derivative part, i came to this result:
What do can i do from here on, thank you!
I am unsure how to go about this. I tried following the suggestion blindly and end up with with some cumbersome terms that are not the answer. From what I understand the derivative at each point would equal to T?
Answer: I just can seem to get to this. I think I'm there but can't get it in...
Matt and Hugh play with a tennis ball and a brick. Then they do some working out to derive the formula for the centripetal force (a = v^2/r) by differentiati...
Calculation of Fourier Transform Derivative d/dw (F{x(t)})=d/dw(X(w))
Hello to my Math Fellows,
Problem:
I am looking for a way to calculate w-derivative of Fourier transform,d/dw (F{x(t)}), in terms of regular Fourier transform,X(w)=F{x(t)}.
Definition Based Solution (not good enough):
from...
As far as I understand, when we want to differentiate a vector field along the direction of another vector field, we need to define either further structure affine connection, or Lie derivative through flow. However, I don't understand why they are needed. If we want to differentiate ##Y## in...
Many have probably seen an example of a function that is continuous at only one point, for example
##f:\mathbb{R}\rightarrow\mathbb{R}\hspace{5pt}:\hspace{5pt}f(x)=\left\{\begin{array}{cc}x, & \hspace{6pt}when\hspace{3pt}x\in\mathbb{Q} \\ -x, &...
Edit: I see this was discussed in the related thread sorry for a repost.
If acceleration causes a change in velocity, and jerk causes a change in acceleration, snap causes a change in jerk, crackle causes a change in snap, pop causes a change in crackle, stop causes a change in pop, drop causes...
For example integral of f(x)=sqrt(1-x^2) from 0 to 1 is a problem, since the derivative of the function is -x/sqrt(1-x^2) so putting in 1 in the place of x ruins the whole thing.
In Paul Nahin's book Inside Interesting Integrals, on pg. 113, he writes the following line (actually he wrote a more complicated function inside the integral where I have simply written f(x))...
## \int_0^\phi \frac {d} {dx} f(x) dx =...
<Moderator's note: Moved from a technical forum and thus no template.>
$$\lim_{x\rightarrow 0} (x-tanx)/x^3$$
I solve it like this,
$$\lim_{x\rightarrow 0}1/x^2 - tanx/x^3=\lim_{x\rightarrow 0}1/x^2 - tanx/x*1/x^2$$
Now using the property $$\lim_{x\rightarrow 0}tanx/x=1$$,we have ...
Hi forum.
I'm trying to prove a claim from Mathematical Analysis I - Zorich since some days, but I succeeded only in part.
The complete claim is:
$$\left\{\begin{matrix} f\in\mathcal{C}^{(n)}(-1,1) \\ \sup_{x\in (-1,1)}|f(x)|\leq 1 \\ |f'(0)|>\alpha _n \end{matrix}\right. \Rightarrow \exists...
Hi guys, I am reading my lecture notes for Mechanics and Variations and I am trying to understand the maths here. From what I can see there we differentiated with respect to a derivative. Could you tell me how do we do that? Thanks
Homework Statement
##f(x) = (5x+6)^{10} , f'(x)=?##
Homework Equations
##\frac{d}{dx}x^n = nx^{n-1}##?
3. The Attempt at a Solution [/B]
I do know the solution ##f'(x) = 50(5x+6)^9##,but I don't know how this solution came to be.I downloaded this problem from the web and it only comes with...
A total derivative dU = (dU/dx)dx + (dU/dy)dy + (dU/dz)dz. I am unsure of how to use latex in the text boxes; so the terms in parenthesis should describe partial differentiations.
My question is, where does this equation comes from?
Homework Statement
Two balls of mass m are attached to ends of two, weigthless metal rods (lengths l1 and l2). They are connected by another metal bar.
Determine period of small oscillations of the system
Homework Equations
Ek=mv2/2
v=dx/dt
Conversation of energy
2πsqrt(M/k)
The Attempt at a...
Recently I came up with a proof of “ for a nth degree polynomial, there will be n roots”
Since the derivative of a point will only be 0 on the vertex of that function,and a nth degree function, suppose ##f(x)##has n-1 vertexes, ##f’(x)## must have n-1 roots.
Is the proof valid?
We define the differential of a function f in
$$p \in M$$,
where M is a submanifold as follows
In this case we have a smooth curve ans and interval I $$\alpha: I \rightarrow M;\\ \alpha(0)= p \wedge \alpha'(0)=v$$.
How can I get that derivative at the end by using the definitions of the...
Homework Statement
If I have the following expansion
f(r,t) \approx g(r) + \varepsilon \delta g(r,t) + O(\varepsilon^2)
This means for other function U(f(r,t))
U(f(r,t)) = U( g(r) + \varepsilon \delta g(r,t)) \approx U(g) + \varepsilon \delta g \dfrac{dU}{dg} + O(\varepsilon^2)
Then up to...
In Rudin, the derivative of a function ##f: [a,b] \to \mathbb{R}## is defined as:
Let ##f## be defined (and real-valued) on ##[a,b]##. For any ##x \in [a,b]##, form the quotient ##\phi(t) = \frac{f(t) - f(x)}{t-x}\quad (a < t <b, t \neq x)## and define ##f'(x) = \lim_{t \to x} \phi(t)##, if the...
Hello,
I was wondering. Is the exponential function, the only function where ##y'=y##.
I know we can write an infinite amount of functions just by multiplying ##e^{x}## by a constant. This is not my point.
Lets say in general, is there another function other than ##y(x)=ae^{x}## (##a## is a...
I am aware that the negative derivative of potential energy is equal to force. Why is the max force found when the negative derivative of potential energy is equal to zero?
Homework Statement
Is it possible to accurately approximate the speed of a passing car while standing in the
protected front hall of the school?
Task: Determine how fast cars are passing the front of the school. You may only go
outside to measure the distance from where you are standing to the...
I was taking notes recently for delta y/ delta x and noticed there's more than one way to skin a cat... or is there?
I saw the leibniz
dy/dx,
the triangle of change i was taught to use for "difference"
Δy/Δx,
and the mirror six
∂f/∂x
which is some sort of partial differential or something...
Homework Statement
Homework Equations
The Attempt at a Solution
I am trying to repair my rusty calculus. I don't see how du = dx*dt/dt, I know its chain rule, but I got (du/dx)*(dx/dt) instead of dxdt/dt, if I recall correctly, you cannot treat dt or dx as a variable, so they don't...
Homework Statement
You are applying for a ##\$1000## scholarship and your time is worth ##\$10## an hour. If the chance of success is ##1 -(1/x)## from ##x## hours of writing, when should you stop?
Homework Equations
Let ##p(x)=1 -(1/x)## be the rate of success as a function of time, ##x##...
Homework Statement
This is a silly question,but i have a problem.How do we solve derivative of -x using first principle of derivative. I know that if derivative of x w.r.t x is 1 then ofcourse that of -x should be -1. Also it can be solved by product rule taking derivative of -1.x .
Homework...
Homework Statement
How do we find the derivative of function:
y= √[(1-sinx)/(1+sinx)]
This is the exercise problem from my textbook. I have not covered chain rule yet. So please you basic derivative rules to solve it.
Homework Equations
Here is the answer of derivative given in my textbook...
As part of the work I'm doing, I'm evaluating a contour integral:
$$\Omega \equiv \oint_{\Omega} \mathbf{f}(\mathbf{s}) \cdot \mathrm{d}\mathbf{s}$$
along the border of a region on a surface ##\mathbf{s}(u,v)##, where ##u,v## are local curvilinear coordinates, and where the surface itself is...
Homework Statement
Hi
I'm having a trouble with finding min value of given function: f(x) = sqrt((1+x)/(1-x)) using derivative.
First derivative has no solutions and it is < 0 for {-1 < x < 1} when f(x) is given for {-1 < x <= 1}.
For x = - 1 there is a vertical asymptote and f(x) goes to +...
For the polar equation 1/[√(sinθcosθ)]
I found the slope of the graph by using the chain rule and found that dy/dx=−tan(θ)
and the concavity d2y/dx2=2(tanθ)^3/2
This is a pretty messy derivative so I checked it with wolfram alpha and both functions are correct (but feel free to check in case...
Hi all
I am trying to reproduce some results from a paper, but I'm not sure how to proceed. I have the following: ##\phi## is a complex matrix and can be decomposed into real and imaginary parts:
$$\phi=\frac{\phi_R +i\phi_I}{\sqrt{2}}$$
so that
$$\phi^\dagger\phi=\frac{\phi_R^2 +\phi_I^2}{2}$$...
We have ##B=(1, X, X^2, X^3)## as a base of ##R3 [X]## and we have the endomorphisms ##d/dX## and ##d^2/dX^2## so that:
##d/dX (P) = P'## and ##d^2/dX^2 (P) = P''##.
Calculating the matrix in class, the teacher found the following matrix, call it ##A##:
\begin{bmatrix}
0 & 1 & 0 & 0...
Homework Statement
Let f(x) be the function whose graph is shown below (I'll upload the image)
Determine f'(a) for a = 1,2,4,7.
f'(1) =
f'(2) =
f'(4) =
f'(7) =
Use one decimal.
Homework Equations
f(x+h)-f(x)/h
The Attempt at a Solution
Hi everybody I was trying to do this function...
GaussianSurface
Thread
calculus
derevation
derivativederivative calculus
function
Homework Statement
Find the divergence of the function ##\vec{v} = (rcos\theta)\hat{r}+(rsin\theta)\hat{\theta}+(rsin\theta cos\phi)\hat{\phi}##
Homework Equations
##\nabla\cdot\vec{v}=\frac{1}{r^2}\frac{\partial}{\partial r}(r^2v_r)+\frac{1}{r sin\theta}\frac{\partial}{\partial...
Homework Statement
The radius of a circle increases from 3 to 3.01 cm. Find the approximate change in its perimeter.
Here's a link to the actual question, in case you need the answer for 6(a) to solve 6(b)
http://imgur.com/a/nQt6M
Homework Equations
Perimeter of circle = 2πr
Area of circle =...