Some Main Ideas You Should Remember

The first part of calculus is about rates of change.
The derivative is just a function that gives the instantaneous rate of change of another function.
The instantaneous rate of change is the slope of the tangent line.
Thus, the derivative of a function gives us information about how the function behaves.
If you look very closely, a function can be approximated by a line.

What ideas do you think you should remember? What are other big ideas from the course?