What about f(x)= x^2, if x < 0 0, if x ≥ 0? It has an inflection point at x = 0 according to your definition. Did you intend this? You didn't show functions like this in your video.
Hello Chris...at 18:08 , is it sufficient to conclude that if f is defined on an interval then accumulation function of f is an anti-derivative of f ? But for instance, if signum function is defined on an interval [-1, 1] then accumulation function is not an anti-derivative of signum function as accumulation function here is not differentiable on (-1, 1).
Polar coordinates are hard to understand and this video was simple to learn the basics. @8:37 when the arctan(2/5) is 0.381 which lies in the range of inverse tan i.e -pi/2 to pi/2 why would we have to go back and add pi to that.
Thanks so much for this video! Do you happen to know which definition for inflection point is used by the College Board for the questions on the AP Calculus exams? I looked in the AP Calculus Course and Exam Description and it didn't seem to say explicitly.
The aluminum on the tops and bottoms of soda cans are twice as thick as the sides. If you change your equation so that the surface area =(4*Pi*R^2)+(2*R*H) to represent using twice the aluminum on the tops and bottoms, then you'll get the right answer. The radius (cube root of 355/4pi) is 3.046 cm, making the height 12.18. Much closer to the 2.7cm - 3.3cm range for the radius and 12.3cm height.
Excellent explanation and visuals. I find myself lost in the text definitions constantly. Supplementing and having a way to visualize what is being stated is integral to my understanding. I appreciate your work 🙏🏻
A little late to the party but consider making a cost function using the surface area (i.e. the aluminum costs some value per square cm). If every part of the can costs the same amount nothing changes (besides maybe a scalar). However, it seems reasonable that the top and bottom material would want to be thicker and say, twice as expensive. This new cost function actually does optimize to something very close to a standard soda can (and of course companies want to optimize cost!).
Great videos, they will be handy next time I teach calc 1 or 2. Thank you for making them! Also, do you mind sharing what you used to make your slides and animations?
Umm.... your endpoint conjecture is absolutely wrong. If end-points are included in the domain of the function and they have a defined value, then they should absolutely be considered for possible global extrema. If an endpoint value is higher (or lower) than all other values, why wouldn't it be a global extrema? Endpoints cannot be relative extrema (by definition), but global extrema may occur at relative extrema and defined end-points. If you do not check defined endpoints for global extrema on any AP Calculus exam or any Calculus entrance exam for any college/university, you will get the problem wrong.
introducing the r/h ration would lead to the same result much easier... in regards of why manufacturer do not follow this rule, it is not only it looks "bigger", but it also the dimater an avarage hand can hold... it would take just some educative facebook campaig to explain that actually the best shape is when the 2r/h ratio is equal to 1...it could save million tons of wasted material
Hi Chris... I have seen about 10 videos on this Law of Cooling... and there were some very good ones.. BUT... Your Video here is the BEST by far!! Thank you for your complete Presentation of all aspects of this Topic.. Amazing!! I am a Subscriber!!
Hi, I have a question regarding the first derivative test and second derivative test. Using the first derivative test and finding critical numbers, testing numbers either side of critical numbers I can determine if function is increasing or decreasing because slope is negative or positive, therefore the critical number itself I can intuitively determine is a relative max or min depending on the test values and where they increase/decrease either side. The second derivative test, find the critical numbers of f’(x), find f”(x) and substitute c.n’s of f’(x) into f”(x), if f”(x) > 0 then minima and same shit/vice versa for maxima if < 0… So if I can determine relative max/min using first or second derivative test, why even use the second? Is it just a preference thing.. ? Some people might like to substitute the value in and know directly… where other people have to use test values / sign diagram for the first derivative test.. but either way.. they give same result don’t they?.. That is what I need clarification on.. They give same RESULT don’t they ??