1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

What is the derivate of this expression?

  1. Jan 20, 2012 #1
    1. The problem statement, all variables and given/known data
    Suppose you have three functions, [itex]f_{1}(x_1),f_{2}(x_2),f_{3}(x_3)[/itex]. Consider the following expression: [itex]H=\int_{0}^{f_{1}(v_1)} G(f_2(\xi))G(f_3(\xi))d\xi[/itex], where [itex] G [/itex] is some continuous function. What is [itex] \frac{\partial H}{\partial x_{j}}[/itex], [itex]j\neq 1[/itex]?

    3. The attempt at a solution

    According to me, all this derivatives are zero. However, I am not quite sure of this because, by applying the chain rule I obtain: [itex] \frac{\partial H}{\partial x_{2}}=\frac{\partial H}{\partial f_{2}}\frac{\partial f_2}{\partial x_{2}}[/itex]. Since [itex]\frac{\partial H}{\partial f_{2}}[/itex] and [itex]\frac{\partial f_2}{\partial x_{2}}[/itex] are both nonzero (known data), then the whole thing should be different from zero. Am I wrong here?
  2. jcsd
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?

Similar Discussions: What is the derivate of this expression?
  1. Derivation question (Replies: 0)

  2. Partial Derivatives (Replies: 0)

  3. Partial Derivatives (Replies: 0)