# First order equations

Get inspired:

On October 14, 2012, Felix Baumgartner skydived from a heigh of 39 km (24 mi), reaching an estimated speed of 1,342 km/hr (834 mph). He descended in free-fall for 4 minutes and 20 seconds. You can watch the footage, which is impressive and scary all at once. At about 2:30 into the video, he starts getting out of his capsule. The camera shot at 3:00 is terrifying. He jumps at 3:34. He deploys his parachute at 7:55. He lands at 12:37. What does this have to do with differential equations? Falling objects are one of the most fundamental problems modeled with first order differential equations.

By the end of this lesson, you should be able to:

• Determine the order of a differential equation – [movie] [notes]
• Check if a function is a solution to a differential equation  – [movie] [notes]
• Explain the difference between a general solution and a particular solution  – [movie] [notes]
• Interpret a first order differential equation as a slope field  – [movie] [notes]
• Solve separable first order equations  – [movie] [notes]
• Determine whether a differential equation is homogeneous – [movie] [notes]
• Solve linear first order differential equations via integrating factors – [movie] [notes]

Before class:

In class, we will: