Geometric Meaning of the Gradient Vector

What direction should you travel to increase your height on a mountain as fast as possible? What direction should you travel to keep your height constant (i.e. travel on a contour aka a level curve)? In this video we discuss the math of this problem, assuming we had some nice function describing the height of the mountain. The gradiant vector, whose components are the respective partial derivatives gives us the answer to the direction of maximal increase. Indeed, we saw previously how directional derivatives could be written in terms of the gradient vector. At the end we look at all of this with an actual topographical map full of contours.
0:00 The Mountain Problem
2:24 Deriving the Gradient Formula
6:07 Directional Derivatives
10:54 Topographical Maps
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Пікірлер: 257

  • @RyanMcCoppin
    @RyanMcCoppin2 жыл бұрын

    I was very confused when people said the gradient was "normal" to the curve. I thought they meant the function itself, not the "level curve". Now it makes complete sense! Thanks!

  • @juanbautistasoria757

    @juanbautistasoria757

    4 ай бұрын

    Same!

  • @sumittete2804

    @sumittete2804

    4 ай бұрын

    Is rate of change of function minimum in the direction of tangent vector or in the direction opposite to gradient vector ?

  • @Suyogya77

    @Suyogya77

    4 ай бұрын

    ​@@sumittete2804 rate of change of the function is minimum in the direction of the tangent vector i.e. in you move perpendicular to the gradient vector

  • @sumittete2804

    @sumittete2804

    4 ай бұрын

    @@Suyogya77 But if i move opposite to gradient vector i.e 180° I'm getting rate of change of function as negative which is less than 0. Moving along tangent vector the rate of change of function is zero. So how ??

  • @Suyogya77

    @Suyogya77

    4 ай бұрын

    @@sumittete2804 do you use telegram or something?

  • @zwhizzo4185
    @zwhizzo41853 жыл бұрын

    This is just brilliant. Clear voice, sound logic and great example.

  • @9888565407
    @98885654073 жыл бұрын

    dude I love ya. that cleared everything about gradients in my mind. Thanks a lot bud.

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    Glad it helped!

  • @destreme9189
    @destreme91892 ай бұрын

    My professor rambled on for 2 hours and I didn't understand anything. Here you are explaining it perfectly in 15 minutes. THANK YOU SO MUCH

  • @dustincondon5557
    @dustincondon55574 жыл бұрын

    Beautifully presented! It's such a cool topic, and using mountains as an analogy makes everything so intuitive.

  • @johnnytoobad7785
    @johnnytoobad77853 жыл бұрын

    Man if my college calculus profs. were as articulate as Dr. Bazett..I would have gotten better grades in those classes. I'm now a retired software "geek" and really love watching these presentations. Very few folks who understand advanced math (and EE-Comp Sci) are good at teaching it to "undergrads". Of course I love the animations also.

  • @codstary1015

    @codstary1015

    Жыл бұрын

    Couldn't agree more, lot of lectures I have i can barely understand what they are trying to present. It's pretty funny that a you tuber can present ideas in a much more clear and straight forward matter.

  • @focusmaestro4013

    @focusmaestro4013

    Жыл бұрын

    @@codstary1015 LOL, Its pretty naive of you to assume that Dr.Trefor is just another youtuber!

  • @chernihivka
    @chernihivka3 жыл бұрын

    great videos, Trefor, I have been looking for the explanations with geometrical insights vs just algebra on the board. This really helps to "see" the math. thanks!

  • @Anonymous-nz8wd
    @Anonymous-nz8wd3 жыл бұрын

    I have never seen such a beautiful explanation ever of Gradients love you

  • @alkankondo89
    @alkankondo894 жыл бұрын

    Great derivation and application! The derivation of the gradient-vector formula and its justification were both quite easy to follow!

  • @milesborowsky8140
    @milesborowsky81404 жыл бұрын

    This is awesome. You're uploading right as I'm learning this material in class, and it's super helpful. I'm a math and education major too - this is such a great conceptual explanation. Thank you!

  • @rafidahmed2796
    @rafidahmed2796 Жыл бұрын

    I usually don't comment on videos but that's the best explanation i've ever watched to understand... i had this confusing for a long time and this lecture cleared that up! you deserve more subs!

  • @Party21304
    @Party21304 Жыл бұрын

    This video is spot on! Very nice. You just clarified gradient, level curves and the directional derivative in an intuitive way. I know understand the meaning behind the math. Thank you so much!

  • @sadpotato5111
    @sadpotato51112 жыл бұрын

    It is a wonderful thing to see your passion about mathematics, I'm assure you it is contagious and I love you because of it. I wish best for you with my all heart. Please do continue to make videos like that.

  • @liuqing1995
    @liuqing19953 жыл бұрын

    The great combination of theory and a real example of a mountain in Vancouver. I enjoy the lesson series of Calculus so much.

  • @zukofire6424
    @zukofire6424 Жыл бұрын

    had seen the videos pop up in the search results and never found the time to have a look. Now just did : I'm a fan! Thanks Prof. Bazett! :)

  • @user-wu8yq1rb9t
    @user-wu8yq1rb9t2 жыл бұрын

    Of course I enjoyed it. For better understanding of the Gradient, I searched this subject, fortunately, I saw you and I just clicked! Thank you so much

  • @minnngb
    @minnngb Жыл бұрын

    i have been looking for a video to help me understand directional derivatives and the gradient for a week and this one was the most helpful!! the visual examples are amazing :)) thank you

  • @PantheraOncaTV
    @PantheraOncaTV2 ай бұрын

    Man, you really teach what's important to understand the concepts, and you explain yourself perfectly! Amazing! You've gained a new subscriber 😁

  • @nicogovindsamy9022
    @nicogovindsamy90224 жыл бұрын

    This video is amazing. First time I'm seeing these concepts clearly since I started taking this course.

  • @walac
    @walac3 жыл бұрын

    Best math channel on KZread!

  • @peterfriedman4912
    @peterfriedman49123 жыл бұрын

    Thank you so much. I read my textbook and understood about half of this material and watched this video a couple of times and now understand the gradient vector much better. You really helped me.

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    Glad it was helpful!

  • @KaviPriyan-qt6vc
    @KaviPriyan-qt6vc4 жыл бұрын

    I am doing all possible steps to take this channel to a bigger audience

  • @engrfawadiqbalkhan786
    @engrfawadiqbalkhan786 Жыл бұрын

    I am a civil engineer , now a days I am pursuing master's in structural engineering ,in structural engineering we use these concepts to find maximum stresses/strains , Before this video I tried a lot but couldn't get into the depth of concept but after watching this video ,I got the concept of it ,animations are very helpful .thankyou and keep up the good work.

  • @ManojKumar-cj7oj
    @ManojKumar-cj7oj3 жыл бұрын

    Thank God I found this channel 🙌

  • @HPLovecraftsCat9
    @HPLovecraftsCat9 Жыл бұрын

    Thank you for this video. You are a very clear example of the fact that you don't need 3Blue1Brown levels of visual editing in order to explain something intuitively and clearly.

  • @Conorstew
    @Conorstew3 жыл бұрын

    My new favourite video of yours, the mountain example was great :) You taught me calc1 at Uvic last year and now you are teaching me calc 3. A true godsend, thanks Trefor!

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    Thanks Conor, really appreciate that. Good luck with math 200!

  • @wildertapiasaenz2333
    @wildertapiasaenz23332 ай бұрын

    I found myself really “down the rabbit hole” with this concept because it just doesn’t mean anything until you visualise it. Your videos really helped me, thank you 🙏

  • @hope-wq9jd
    @hope-wq9jd2 жыл бұрын

    after visualizing these concepts it became easier for me to perform the mathematical formulas thank you so much sir for the valuable information

  • @viniciusdeobber8239
    @viniciusdeobber82392 жыл бұрын

    Great video, made it easy to understand. Thanks, professor Trefor!

  • @lakshitha99
    @lakshitha992 жыл бұрын

    Best math channel. Massive respect. Thank you sir..❤️

  • @sergiolucas38
    @sergiolucas382 жыл бұрын

    excellent video as always, nice example :)

  • @TheWildStatistician
    @TheWildStatistician7 ай бұрын

    Absolutely fantastic explainer! Way to go!

  • @ikarus1060
    @ikarus10603 жыл бұрын

    Ahhh, finally I fully got it, thx man:) The map help a lot. I knew what gradient is, but i strugled to get the geometric meaning

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    Glad it helped!

  • @nadenglish3811
    @nadenglish38113 жыл бұрын

    amazing and so interesting! keep it up

  • @aln4075
    @aln40754 ай бұрын

    this video is one of the greatest one's that you can find on this topic

  • @LinLin-rs2bv
    @LinLin-rs2bv2 жыл бұрын

    Great video that gives a brilliant straight explanation for the gradient vector. Hope to have your class in UVic.

  • @ishraqhossain1235
    @ishraqhossain12354 жыл бұрын

    your bio says you try to do "evidence based pedagogical practices". This is just beautiful man. Hope you come up with more intuitive calculus videos

  • @RSS18
    @RSS182 жыл бұрын

    Perfectly explained. Thank you sir

  • @julioreyram
    @julioreyram3 жыл бұрын

    Brilliant explanation again :). It would be very good if you linked the previous explanations, i.e., the tension vector.

  • @rupaupadhaya8888
    @rupaupadhaya88882 жыл бұрын

    This video is really helpful. Thank you so much,👏

  • @at6727
    @at67273 жыл бұрын

    you'll make us love calculus and maths!! thanks for including practical example of Vancouver island

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    haha I had fun with that part!

  • @joaomattos9271
    @joaomattos9271 Жыл бұрын

    Fantastic way of teaching!!! I recommend the classes here in Brazil!

  • @scratchyourhead2383
    @scratchyourhead23832 жыл бұрын

    Thank you sir ❤! You are clearing my such deep buried doubts .

  • @TheEmad619
    @TheEmad6193 жыл бұрын

    thank you so much for clearing the doubt. The video was very helpful.

  • @xiliu3526
    @xiliu35264 ай бұрын

    Such a brilliant video, it truly heps

  • @electricalabc3411
    @electricalabc34113 жыл бұрын

    Example of a mountain was superb to explain gradient..thanks bro

  • @rivkamutka2833
    @rivkamutka2833 Жыл бұрын

    Amazing explanation. Thank you!

  • @youssefdirani
    @youssefdirani2 жыл бұрын

    Super thanks Dr. May you be blessed

  • @sashamuller9743
    @sashamuller97434 жыл бұрын

    awesome stuff! i love this subject

  • @bimankalita2960
    @bimankalita29609 ай бұрын

    I wish there was the option of giving more than one like. Superb explanation!

  • @anandita166
    @anandita1663 жыл бұрын

    thankyou so much! this one's great!!🌟

  • @olehborys1462
    @olehborys1462 Жыл бұрын

    great example, thank you for your video

  • @habilismayilov838
    @habilismayilov838 Жыл бұрын

    Amazing explanation!!!! thank you so much, you make great influence in the world..

  • @joliettraveler
    @joliettraveler3 жыл бұрын

    Fantastic explanation. Now I understand the gradient for our purposes lies in the xy plane and that it points into the mountain.

  • @subhajitbarman4672
    @subhajitbarman46723 жыл бұрын

    Such a clarity in your explanation....thank you so much sir, you cleared my hardest doubt...😊😊❤❤😊❤❤❤

  • @maani315
    @maani3153 жыл бұрын

    Your demonstration is just amazing Sir....the best explanation of gradient vector on KZread....

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    Thanks a ton!

  • @shubhamvadagave8961
    @shubhamvadagave89613 жыл бұрын

    Great explanation! Thanks alot

  • @Indik47
    @Indik478 ай бұрын

    Excellent explanation

  • @maximlavrenko1164
    @maximlavrenko1164 Жыл бұрын

    rewatched it several times, started losing hope but then it clicked and I was like 'wait that makes sense!'

  • @alejrandom6592
    @alejrandom65923 жыл бұрын

    Awesome video!

  • @muktasane6046
    @muktasane6046 Жыл бұрын

    Thanks so much it helped me understand the gradient concept.

  • @chuz1818
    @chuz18183 жыл бұрын

    Amazing explanation! Thank you so much!!

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    Glad you enjoyed it!

  • @gibs40
    @gibs40 Жыл бұрын

    This channel is truly underrated

  • @shashankjhaa6221
    @shashankjhaa6221 Жыл бұрын

    Love your teaching sir...""LOVE""

  • @AS-ix3qd
    @AS-ix3qd3 жыл бұрын

    my mind is blown, finally I understand how the tangent unit vector gives a direction along which f(x,y) is constant, Thx alot Dr.

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    glad it helped!

  • @richardslesinski4137
    @richardslesinski41372 жыл бұрын

    amazingly clear. thank you

  • @MamToCos
    @MamToCos9 ай бұрын

    Good works! Thank you.

  • @ahmadwael8541
    @ahmadwael85413 ай бұрын

    thanks a lot for the great explanation

  • @punditgi
    @punditgi3 жыл бұрын

    Excellent!

  • @naikyasir2871
    @naikyasir2871 Жыл бұрын

    Really enjoyed

  • @wandrew307
    @wandrew30729 күн бұрын

    Amazing, Thank you!

  • @AutiEShap
    @AutiEShap7 ай бұрын

    A legend is living among us!!!!!!!!!

  • @thisukainol
    @thisukainol3 ай бұрын

    wow. great explanation

  • @AK-sh8df
    @AK-sh8df2 жыл бұрын

    Wonderful video

  • @somanathdash3153
    @somanathdash31533 жыл бұрын

    Oh god it helped me so much thanks sensai

  • @vaibhavgaur261
    @vaibhavgaur2612 жыл бұрын

    bruh, u nailed it🙏🙏

  • @noonesland2471
    @noonesland24713 жыл бұрын

    I love you, thank you!

  • @optimistprime6741
    @optimistprime67412 жыл бұрын

    You’re literally perfect

  • @edgbaston149
    @edgbaston1493 жыл бұрын

    Thank you so much🙏 You're amazing. 😊😎

  • @user-do1kj6ov6z
    @user-do1kj6ov6z Жыл бұрын

    It's awesome interpretation💖

  • @chrismarklowitz1001
    @chrismarklowitz1001 Жыл бұрын

    I like to think of the normal vector to the contour plot as the shortest distance between two points is a straight line. And when the distance between them next contour is infinitesimal. It is a parallel line. And anything other than normal is going to be more than just going normal.

  • @hemrajkumawat801
    @hemrajkumawat8013 жыл бұрын

    Just amazing

  • @shivarapolu3180
    @shivarapolu31803 жыл бұрын

    understood the beauty of multivariable calculus and gradient operator. Thanks a lot sir :)))

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    Happy to help!

  • @shreyapandey7154
    @shreyapandey715411 ай бұрын

    very informative

  • @khaishchadha5094
    @khaishchadha50943 жыл бұрын

    you r a god.love your videos

  • @rizalpurnawan3796
    @rizalpurnawan37963 жыл бұрын

    Amazing lecture! It essentially proves the notion that the gradient is orthogonal to the level set. Thanks a lot Sir Trefor.

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    You are welcome!

  • @sumittete2804

    @sumittete2804

    4 ай бұрын

    Is rate of change of function minimum in the direction of tangent vector or in the direction opposite to gradient vector ?

  • @carultch

    @carultch

    4 ай бұрын

    @@sumittete2804 The direction of the gradient tells you the direction of steepest ascent, and the magnitude tells you the slope of that ascent. Opposite the gradient vector, is the direction of steepest descent. The rate of change of the function is minimized, if the input point travels perpendicular to the gradient vector. The contour lines are perpendicular to the gradient vector. The principle behind Lagrange multipliers comes from this idea. Given that the point in question follows a constrained path, the candidates for the local extreme value of the function's output will occur when the path and the contour line, share a common direction.

  • @pawanadhikari110
    @pawanadhikari1103 жыл бұрын

    Absolute trivial explanation.

  • @Silver-bq6td
    @Silver-bq6tdАй бұрын

    great job.

  • @continnum_radhe-radhe
    @continnum_radhe-radhe2 жыл бұрын

    Thanks a lot sir 🔥🔥🔥

  • @BscPhysicsRGLectures
    @BscPhysicsRGLectures3 жыл бұрын

    Love you sir!

  • @nickknight5373
    @nickknight53733 жыл бұрын

    Very well-explained.

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    Glad you think so!

  • @santhoshkumar-lv4ph
    @santhoshkumar-lv4ph3 жыл бұрын

    I love so much u are a genius teacher

  • @tanayasharma7776
    @tanayasharma77763 жыл бұрын

    my favorite math teacher on youtube

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    Thank you!

  • @pitiwatkittiwimonchai4656
    @pitiwatkittiwimonchai46562 жыл бұрын

    I love it Great sir

  • @sujithkumar7158
    @sujithkumar71583 жыл бұрын

    Simply Brilliant

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    Thank you!

  • @rupanzilmamunprince
    @rupanzilmamunprince3 жыл бұрын

    what an amazing video!!! Please make a video on divergence on curl too...it would be very helpful

  • @rupanzilmamunprince

    @rupanzilmamunprince

    3 жыл бұрын

    @@DrTrefor Wow!! Eagerly waiting for them

  • @sherin5566
    @sherin55663 жыл бұрын

    woww..!! Subscribed

  • @DrTrefor

    @DrTrefor

    3 жыл бұрын

    thank you!

  • @aryanraj3921
    @aryanraj39212 жыл бұрын

    Thanks a lot sir...

  • @Alannnn14
    @Alannnn143 жыл бұрын

    Thank you very much

  • @ZoinkDoink
    @ZoinkDoink3 жыл бұрын

    GREAT video, solid explanation. but i have a question. was the gradient defined originally in terms of the directional derivative?