Approaching Jacobian Calculation for a Single Function with Multiple Variables

  • Thread starter Thread starter ver_mathstats
  • Start date Start date
  • Tags Tags
    Function Jacobian
ver_mathstats
Messages
258
Reaction score
21
Homework Statement
We must find the Jacobian of f(s,r,t)=s^2+sin(rt)-3. Compute J(f/s)(1, pi, -1).
Relevant Equations
f(s,r,t)=s^2+sin(rt)-3. Compute J(f/s)(1, pi, -1).
I'm used to calculating Jacobians with several functions, so my only question would be how do I approach solving this one with only one function but three variables?

I think our function becomes (s^2+sin(rt)-3)/since we are looking for J(f/s). So then would our Jacobian simply be J=[∂f/∂s ∂f/∂r ∂f/∂t] with finally our values substituted of (1, pi,-1)?
 
Physics news on Phys.org
Yes. The Jacobi matrix is simply the gradient in this case.
 
  • Like
Likes ver_mathstats
fresh_42 said:
Yes. The Jacobi matrix is simply the gradient in this case.
Thank you, and sorry for the typo, I had meant "I think our function becomes (s^2+sin(rt)-3)/s since we are looking for J(f/s)."
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...
Back
Top