My Math Forum  

Go Back   My Math Forum > College Math Forum > Calculus

Calculus Calculus Math Forum


Reply
 
LinkBack Thread Tools Display Modes
July 14th, 2015, 01:13 PM   #1
Member
 
Joined: Sep 2013

Posts: 58
Thanks: 0

Gradient Question

So I don't get what I did wrong either.
fx(1.3)=-6x=-6(1)=-6
fy(1,3)=-6y=-6(3)=-18
Gradiant <-6,-18>
Length is Sqrt((-6)^2+(-1^2)=Sqrt(360). Unit Vector =1/sqrt(360)<-6,-18>
b)
I'm not sure if we find the Length of the Gradiant Vector of length of the Unit Gradiant Vector
Gradiant <-6,-18>
Length of Gradiant: Sqrt(360)

What am I doing wrong?
--------------------------------------------------------------------------------------------------------------
Tzad is offline  
 
July 14th, 2015, 02:18 PM   #2
Member
 
Joined: Sep 2013

Posts: 58
Thanks: 0

Nevermind.

The question asks for the fastest descent (slope is negative), while the gradient always gives the fastest ascent (where the slope is positive. I needed to multiple the vector<-6,-8> by negative one to get to a unit vector of 1/sqrt(360)<6,18> and hence a fastest downward speed of -sqrt(360).

Sorry for the trouble. You can close the thread.

From,

Tzad
Tzad is offline  
Reply

  My Math Forum > College Math Forum > Calculus

Tags
gradient, question



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
gradient of y= -2x +8 ?? coachcft Calculus 2 December 15th, 2012 01:25 PM
Gradient truthseeker Linear Algebra 12 October 2nd, 2012 08:07 AM
Gradient veronicak5678 Real Analysis 0 May 6th, 2012 10:08 AM
Differentiating the gradient? Weijingren Calculus 1 January 20th, 2009 03:20 AM
The value of g in the gradient formula dthomas86 Algebra 3 December 31st, 1969 04:00 PM





Copyright © 2017 My Math Forum. All rights reserved.