How to Get Started, Doing Things that Don't Scale, and Press (How to Start a Startup 2014: 8)

[Applause] [Music] So, how does the spinning tube trick work? Well, a lot of you identified that the tube is rotating about its long axis, and it’s also rotating horizontally about its middle. But how does that allow us to see one symbol and not the othe…

What is the equation of the horizontal line through the point (-4, 6)? So, let’s just visualize this. Once you get the hang of it, you might not have to draw a graph, but for explanatory purposes, it might be useful. So, (-4, 6), so that’s going to be i…

This is from the graph basic exponential functions on KH Academy, and they ask us to graph the following exponential function. They give us the function ( H(x) = 27 \cdot \left(\frac{1}{3}\right)^x ). So our initial value is 27, and ( \frac{1}{3} ) is our…

Hi everyone, Sal here with my three-year-old son Azad, and we’re excited to announce the launch of Khan Academy Kids, which is designed to take students like Azad, ages two to five, to become lifelong learners. Hi friends, welcome to my room! Kids love t…

How the economic machine works in 30 minutes. The economy works like a simple machine, but many people don’t understand it, or they don’t agree on how it works, and this has led to a lot of needless economic suffering. I feel a deep sense of responsibili…

You know, there are essential tools for birding: your binoculars, your spotting scope, your field guide, and if you’re black, you’re going to need probably two or three forms of ID. Never wear a hoodie. The word for an African-American and camouflage is “…