Derivative as slope of a tangent line | Taking derivatives | Differential Calculus | Khan Academy

Understanding that the derivative is just the slope of a curve at a point (or the slope of the tangent line)

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Differential calculus on Khan Academy: Limit introduction, squeeze theorem, and epsilon-delta definition of limits.

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[kategard]

Mr Khan, has anyone ever told you...you the man?

[reindeerman]

Holy shit math makes more sense in English than in Swedish:/.  

[giorgioapple]

Seems so weird in college but with these videos these subjects seem to be easy enough for kids to learn.

[jriver]

Believe it or not, you're the only individual on this earth made it possible for me to understand this section of Calculus. In fact, you have a gift of lecturing on this subject matter with complete ease of simple demonstration. Thank you.

[merc]

Khan Academy I just wanna say that in the first four minutes alone, I have learned and understood what a slope is from this video!! More than I did last year from the tutor and learning program! I have math avoidance (among other things) and I FINALLY can understand the concept of a slope! I'm grateful for that. So, thank you Khan Academy.

[TeodoraMateeva]

Sal's videos are like enlightnment coming from the cosmos and shining through my brain :D

[abbasmawash]

Ive been in school for 12 years and never realized the meaning of the slope of tangent to the curve
Thank you very much

[Austin_Schulz]

Shot game:
Every time Sal says "Let me try a different color." take a shot.
Every time said color is magenta, take TWO shots. 

[dancetron]

(Not) he said a bunch in this video. After looking that up its simply a short hand for notation in case anyone was wondering the same thing I had.

[SDEliptiK]

you just have a flawless way of teaching things

[jrcr]

Oh my god, you taught in 15 min what my math teacher taught me in a week. You're so helpful..Thanks to you i can understand derivatives once for all. thanks!

[johnsono]

wow! beautiful explanation. Got me clapping in my school library

[suprdbgt]

Thank you very much. I finally got this concept through my head.

[Loriixoxo]

the HD videos are much better and easier to follow than some of the old videos, because the lines used to write are crisper, rather than all sketchy. I'm so glad you're taking the time to re-do some of the videos in HD quality. Did you just get a new program to make your videos with? Before, your pointer looked like a regular arrow mouse icon, and now its a crosshair... also, I think you were using a mouse before to do your videos, and now it looks like you're using a tablet. Just curious.

[antoniro]

I always asked myself what kind of software you use for writing...

[vovven]

Sal, I spend more time with you then my friends! You are my dearest friend ;)

[tony]

Great. it's better than the standard-def version.
Just a tip, turn off the noise suppression and/or cancellation on your audio software (your voice will be better quality)

[diceman]

why is it that every youtube instructer explains it 10 times better than any professor I ever had?

[pageerror]

Me: Excuse me, I'm having trouble understanding exactly what a derivative is.
Math Teacher: It's f(x+h) - f(x) / h
Me: *sigh*

Seriously I spent a while semester pretending to know what a derivative meant and now I learned it in 15 minutes lol.

[bsivoljr]

Lol you def need your book for practice to say the least. Khan Academy has been the single most effective study supplement I have ever encountered. So many mind booms