Focus and Directrix of a Parabola 2

[WeatheredPilot]

the prettiest math available

[mickstarify]

Thank you! i never understood how until now

[ldy6090]

sdsdsdssd

[ldy6090]

sdsd

[ldy6090]

sdsdssssssssssssss\



[chineee123]

ahhh makes SENSE finally xD

thanks, Sal

[JohnCKovach]

They still leave the most important properties of the Focal Point and the Directrix of Parabolas when learning the mathematics and physics! Parallel light rays coming into a parabollic dish(mirror) reflect to a common point creating incredible energy (heat);example a solar furnace or waves coming in from a satellite would be collected on a probe holding a receier at the focal point.

The Directrix could be illustrated in the 'Bow Wave' that appears in front of the Vortex. Why?

[VoidJuggernaut]

MAGENTA!

[VoidJuggernaut]

and then we did A BUNCH OF ALGEBRA... and got this equation right here *points at pretty equation*

[ItsNeuroscience]

"the color choosing is the hard part"

[jimmytangy]

I wish my math teacher would teach this way instead of teaching us how to plug in numbers into formulas like a calculator :D This actually gets me interested in learning math.

[aeropostale]

i wish you would just tell us how to solve the problems instead of explaining everything. i know its helpful for some ppl but it just confuses me a lot

[thejugglenaut91]

@aeropostale that's how public school works. The reason you're confused is because you don't understand something or you don't understand something that came before this.

[jmm00702]

@aeropostale u must learn and understand all of that in university exams, so this guy's help is really useful. Until then ud better not watch his vids, just learn a bunch of formulas and ull be fine.

[fatboy2oo]

@jmm00702 That's not entirely true. Most Professors only care that you can use the formulas. Only a few of them spend all of the class time explaining theory and not a lick of practice. Nonetheless. As an Engineering Major, I feel that an understanding of the underlying principles of why things add up to be the way they are is important. But it isn't necessary for everyone.

[twirmd]

@aeropostale You're definitely not going to go far beyond high school academically if you're too intellectually lazy to wonder why things work the way they do.

[cowfinatic101]

it mostly all came togather in the last 30seconds lol.

[VoidJuggernaut]

@cowfinatic101 LOL THATS WHAT I THOUGHT! >.>

[ironmaidenrules12345]

thanks a lot but i really wish you would've put in random numbers, the variables keep getting me confused. but stil 5/5.

[aajalexjames69]

I'm a maths teacher myself and this is an amazing way to explain this topic! nice one mate!

[maijib2009]

I am so sorry, I just want to ask about the parabola, it only has 3 points it means I have to draw a line from point to point, therefore I only get a V shape. to get a smooth curve line I have to make 1,000 points and then connect each point with a line. I never understand. I am talking about Algebra, Calculus and Geometry.

I never understand about curve lines in 3 or 4 points it must be 1,000 points in a small area to make a smooth curve line.

Thanks and have a nice day.

[OmgMinaRawr]

@maijib2009

yes there are many points in a parabola

but idt you dont have much time to actually make so many points...so thats why we pretty much stick with drawing a few points instead of a thousand of 'em

[Mika162]

magnificent video what a explanation Cheers!!!! Keep putting video it is really soothing to hear your explaination of directrix and parabola great

[ose90]

Thanks a lot Sal, you are amazing :)

Completely mastered conic section now,otherwise still have to revise before exams!

[Jakers2009]

u really are an amazing teacher Sal! By the way just out of interest - did u every fail an exam?