Directional derivative

posted by .

"Find the directional derivative fu(1,2) for the function f with u = (3i-4j)/5 for f(x,y)= x^(2) - y^(2)."

Thank you!

  • Directional derivative -

    df(x,y)/dx = 2x
    df(1,2)/dx = 2
    df(x,y)/dy = -2y
    df(1,2)/dy = -4
    Directional derivative =
    = <2,-4> • <(3/5),-(4/5)>
    = (6/5) + (16/5)
    = 22/5

Respond to this Question

First Name
School Subject
Your Answer

Similar Questions

  1. Calc

    a) y =ln(x-1) find dy/dx=? b) y=3 ln x - ln (1/x) where x >0, dy/dx= ?
  2. Calc

    The directional derivative of z = f(x,y) at (2,1) in the direction toward the point (1,3) is -2/sqrt(5), and the directional derivative in the direction toward the point (5,5) is 1. Compute dz/dx and dz/dy at (2,1). I have no idea …
  3. Environmental Science

    I have to determine which kind of natural selection is most likely to begin speciation out of stabalizing, directional and disruptive. I would think Directional, since it favors one extreme which could eventually break away from the …
  4. cal3

    Consider the function f(x,y)=xy+xz+yz+4 at point p=(2,-1,1) a)find the unit vector in direction of p. b) find the directional derivative at p in the direction of <0,-1/(sqrt2),-1/(sqrt2)>
  5. calculus

    Find the derivative of the function using the definition of derivative. g(t)= 9/sqrt(t) g'(t)= state the domain of the function and the domain of the derivative (use interval notation)
  6. math

    Let f be a real value function and x Î Df then 0 lim ( ) ( ) h f x h f x ® h + - when it exists is called A) The derivative of f at a B) The derivative of f at h C) The derivative of f at x D) The derivative of f at x = h

    Find the gradient and directional derivative of f at P in the direction of v: f(x,y)=ln(x^2 + y^2 +1)+ e^(2xy) P(0,2) v=5i-12j
  8. calc

    3. If f(x, y)=5 − 4x3 + 8y2, find a unit vector ~u for which the directional derivative D~uf(1, 1) is zero. im not sure how to do this one
  9. mathematical physics

    Determine the directional derivative of phi =xy^z in the direction i^-2j^+2k^ at the point (3, 1, -1)
  10. maths plz help

    Find the directional derivative of: ∅=(x+2y+z)²—(x—y—z)² at the point (2, 1, -1) in the direction of A=i—4j+2k. Plz help show me work

More Similar Questions