A community for students.

Here's the question you clicked on:

55 members online
  • 0 replying
  • 0 viewing

anonymous

  • 5 years ago

how is f x y = (-y sin xy)(x) = -xy sin xy ?

  • This Question is Closed
  1. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    how to solve this second order partial derivative? when function f(x,y) =Sin xy.....??? i have differentiated w.r.t. x and got \[-y ^{2} Sin xy\] but to find 2nd order part. derv. i have differentiated this w.r.t. y and i have got \[-xy Sin xy -\cos xy\] is this correct?

  2. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    is it?

  3. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    When you take a partial w.r.t. x you hold y as a constant, so: \[D_x=-ysin(xy)-xy^2\cos(xy)\]

  4. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    plz hold on..i'll type how i had solved...

  5. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    function is 'Sin xy' part.derv. wrt x=y cos xy -------eq. 1 part.derv. of eq .1 wrt x= \[-y ^{2} \sin xy\] and part.derv of eq 1 wrt y is = \[-xy \sin xy-\cos xy \] (using uv rule)

  6. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    is the part.derv. of eq 1 wrt y correct?

  7. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    to find part.derv. of eq 1 wrt 'y' :- \[u= y \cos xy & v=\cos xy\] then, \[{y(- \sin xy)x}-{\cos xy .1}\] and thats how i got −xysinxy−cosxy

  8. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    u=y and v=cos xy

  9. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    are you getting the same answer?

  10. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    u der?

  11. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    I thought your function was -xysin(xy)......? your partial w.r.t. x is correct what are you trying to find out ? \[f_x(x,y), f_y(x,y), or, f_{xy}(x,y)\]

  12. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    the actual function is f(x,y)=Sin xy \[f_{x} (x,y)= y Cos xy \] , \[f _{xx}= - y ^{2} Sin xy \] and \[f _{xy}(x,y)= -xy Sin xy+\cos xy\]

  13. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    is this correct???

  14. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    Yes, thats correct

  15. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah i got the answer

  16. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    yeah i got the answer

  17. anonymous
    • 5 years ago
    Best Response
    You've already chosen the best response.
    Medals 0

    cool

  18. Not the answer you are looking for?
    Search for more explanations.

    • Attachments:

Ask your own question

Sign Up
Find more explanations on OpenStudy
Privacy Policy

Your question is ready. Sign up for free to start getting answers.

spraguer (Moderator)
5 → View Detailed Profile

is replying to Can someone tell me what button the professor is hitting...

23

  • Teamwork 19 Teammate
  • Problem Solving 19 Hero
  • You have blocked this person.
  • ✔ You're a fan Checking fan status...

Thanks for being so helpful in mathematics. If you are getting quality help, make sure you spread the word about OpenStudy.

This is the testimonial you wrote.
You haven't written a testimonial for Owlfred.