I have a discrete function $I(V)$ which is defined as $$I(V) = R\big(V\big) * Q \big(V \big) = \int_a^b R\big(V\big) Q \big(V-V' \big) dV'$$ and I want to find $\frac{\partial^2R}{\partial V^2}$ but do not know $Q \big(V \big)$. I am able to take the second derivative of $I(V)$ via finite difference: $$\frac{\partial^2I}{\partial V^2} \approx \frac{I(V+V_{0})+I(V-V_{0})-2I(V)}{V_{0}^2}$$ and I know that derivatives can be applied to either function in a convolution: $$\frac{\partial^2I}{\partial V^2} = \frac{\partial^2R}{\partial V^2} * Q \big(V \big) = R \big(V \big) * \frac{\partial^2Q}{\partial V^2} = \frac{\partial R}{\partial V} * \frac{\partial Q}{\partial V}$$ I also know that the process of taking the second derivative of a discrete function is the equivalent of convolving the function with the 3x3 Toeplitz matrix: $$\begin{bmatrix}-2 & 1 & 0\\1 & -2 & 1\\0 & 1 & -2\end{bmatrix}$$ Can I find either $\frac{\partial^2R}{\partial V^2}$ or $Q \big(V \big)$ if I know $I(V)$ (and therefore $\frac{\partial^2I}{\partial V^2}$)?
2026-03-25 17:45:24.1774460724
Second derivative finite difference of a convolution of two functions.
412 Views Asked by Bumbble Comm https://math.techqa.club/user/bumbble-comm/detail AtRelated Questions in INTEGRATION
- How can I prove that $\int_0^{\frac{\pi}{2}}\frac{\ln(1+\cos(\alpha)\cos(x))}{\cos(x)}dx=\frac{1}{2}\left(\frac{\pi^2}{4}-\alpha^2\right)$?
- How to integrate $\int_{0}^{t}{\frac{\cos u}{\cosh^2 u}du}$?
- Show that $x\longmapsto \int_{\mathbb R^n}\frac{f(y)}{|x-y|^{n-\alpha }}dy$ is integrable.
- How to find the unit tangent vector of a curve in R^3
- multiplying the integrands in an inequality of integrals with same limits
- Closed form of integration
- Proving smoothness for a sequence of functions.
- Random variables in integrals, how to analyze?
- derive the expectation of exponential function $e^{-\left\Vert \mathbf{x} - V\mathbf{x}+\mathbf{a}\right\Vert^2}$ or its upper bound
- Which type of Riemann Sum is the most accurate?
Related Questions in DERIVATIVES
- Derivative of $ \sqrt x + sinx $
- Second directional derivative of a scaler in polar coordinate
- A problem on mathematical analysis.
- Why the derivative of $T(\gamma(s))$ is $T$ if this composition is not a linear transformation?
- Does there exist any relationship between non-constant $N$-Exhaustible function and differentiability?
- Holding intermediate variables constant in partial derivative chain rule
- How would I simplify this fraction easily?
- Why is the derivative of a vector in polar form the cross product?
- Proving smoothness for a sequence of functions.
- Gradient and Hessian of quadratic form
Related Questions in CONVOLUTION
- What is the result of $x(at) * δ(t-k)$
- Convolution sum
- PDF of the sum of two random variables integrates to >1
- If $u \in \mathscr{L}^1(\lambda^n), v\in \mathscr{L}^\infty (\lambda^n)$, then $u \star v$ is bounded and continuous.
- Proof of Young's inequality $\Vert u \star v \Vert_p \le \Vert u \Vert_1 \Vert v \Vert_p.$
- Duhamel's principle for heat equation.
- Computing the convolution of $f(x)=\gamma1_{(\alpha,\alpha+\beta)}(x)$
- Convolution of distributions property
- Self-convolution of $f(\vec{r}) = e^{-x^2-y^2}/r^2$
- Inverse $z$-transform similar to convolution
Related Questions in FINITE-DIFFERENCES
- 4-point-like central finite difference for second partial derivatives
- Numerical method for fourth order PDE.
- Finite difference approximation of $u''(x)+u(x)=0, u(0)=1, u(\pi)=-1$
- Numerically compute Laplacian of a scalar field in a non-orthogonal grid
- write second order difference as a convolution operator
- Do the second differences of the fifth powers count the sphere packing of a polyhedron?
- Discretization for $\partial_tu = \partial_x[g\times\partial_xu]$
- Discretization of 4th order ODE
- Trying to use Matlab to find Numerical Solution to $u''(x)+e^{u(x)}=0, u(0)=0, u(1)=0$ - Newton's method
- Finite difference: problem on edge of Dirichlet and Neumann boundary
Trending Questions
- Induction on the number of equations
- How to convince a math teacher of this simple and obvious fact?
- Find $E[XY|Y+Z=1 ]$
- Refuting the Anti-Cantor Cranks
- What are imaginary numbers?
- Determine the adjoint of $\tilde Q(x)$ for $\tilde Q(x)u:=(Qu)(x)$ where $Q:U→L^2(Ω,ℝ^d$ is a Hilbert-Schmidt operator and $U$ is a Hilbert space
- Why does this innovative method of subtraction from a third grader always work?
- How do we know that the number $1$ is not equal to the number $-1$?
- What are the Implications of having VΩ as a model for a theory?
- Defining a Galois Field based on primitive element versus polynomial?
- Can't find the relationship between two columns of numbers. Please Help
- Is computer science a branch of mathematics?
- Is there a bijection of $\mathbb{R}^n$ with itself such that the forward map is connected but the inverse is not?
- Identification of a quadrilateral as a trapezoid, rectangle, or square
- Generator of inertia group in function field extension
Popular # Hahtags
second-order-logic
numerical-methods
puzzle
logic
probability
number-theory
winding-number
real-analysis
integration
calculus
complex-analysis
sequences-and-series
proof-writing
set-theory
functions
homotopy-theory
elementary-number-theory
ordinary-differential-equations
circles
derivatives
game-theory
definite-integrals
elementary-set-theory
limits
multivariable-calculus
geometry
algebraic-number-theory
proof-verification
partial-derivative
algebra-precalculus
Popular Questions
- What is the integral of 1/x?
- How many squares actually ARE in this picture? Is this a trick question with no right answer?
- Is a matrix multiplied with its transpose something special?
- What is the difference between independent and mutually exclusive events?
- Visually stunning math concepts which are easy to explain
- taylor series of $\ln(1+x)$?
- How to tell if a set of vectors spans a space?
- Calculus question taking derivative to find horizontal tangent line
- How to determine if a function is one-to-one?
- Determine if vectors are linearly independent
- What does it mean to have a determinant equal to zero?
- Is this Batman equation for real?
- How to find perpendicular vector to another vector?
- How to find mean and median from histogram
- How many sides does a circle have?