Finding average rate of change of polynomials | Algebra 2 | Khan Academy

Keep going! Check out the next lesson and practice what you’re learning:

Finding the average rate of change of f(x)=x³-4x over the interval [-2,3].

Khan Academy is a nonprofit organization with the mission of providing a free, world-class education for anyone, anywhere. We offer quizzes, questions, instructional videos, and articles on a range of academic subjects, including math, biology, chemistry, physics, history, economics, finance, grammar, preschool learning, and more. We provide teachers with tools and data so they can help their students develop the skills, habits, and mindsets for success in school and beyond. Khan Academy has been translated into dozens of languages, and 15 million people around the globe learn on Khan Academy every month. As a 501(c)(3) nonprofit organization, we would love your help!

[hydradestroyer]

This confused me so much I feel like I LOST brain cells

[nate]

Doing this over the summer to relearn before school :/

[nathanielbailey]

this is why I hate math. Crap is just drawn out of thin air and youre expected to understand it. What a useless skill to those without telekinesis

[kwabenaprempeh]

Why change in x is positive 5. I'm lost. I need explanation

[nathanielbailey]

very confused yet again towards the end. Why is the line shaped like that, and no just a straight line from Point A to point B? There is no given reason here or in the prior lesson as to why the line would curve twice like that. It's also no obvious to me why 15/5 was reduced to 3/1 if we were going to move the line to the (3/15) coordinate. (which also doesnt make sense, as youre combining 3/1 and 15/5 to get (3, 15). This doesnt match how you came up with the (-2, 0) coordinate which made more sense. And you want donations for helping us learn!?!?!

[nathanielbailey]

I assume that the (-2, 3) is a coordinate (x, y) on a graph. If that is so why do you find each as x? Wouldn't the second digit be x=f(y)? Why is it laid out this way? Am I wrong? Is the function pair not an x y coordinate? If it is a coordinate, why does it seem like X and Y are used to symbolize variables differently than they symbolize variable coordinates?

[AileenLiu-fs]

So you basically mean the average rate of change of polynomials are SLOPE 😑😑

[nathanielbailey]

and your stupid website wont let me get help because I dont have magical "energy points" fairy dust and my account isnt verified even though you never sent a verification link.

Anyone know of a better resource than kahn for re-learning algebra and calc outside of school? I'm sinking.