Horizontal Tangent Lines and Differentiation Calculus 1 AB

I explain how to find the domain values where a curve has a slope of zero using the first derivative. I also explain how we can look at the sign changes of the first derivative to identify relative maximums and minimums. ERROR NOTICE: In the last example I only did solutions for x restricted to [0,2pi). Without this restriction the solutions should have been expanded to include all possible solutions. x=π/2+nπ, π/6+2nπ and 5π/6+2nπ. Check out http://www.ProfRobBob.com, there you will find my lessons organized by class/subject and then by topics within each class. Find free review test, useful notes and more at http://www.mathplane.com If you'd like to make a donation to support my efforts look for the "Tip the Teacher" button on my channel's homepage    / profrobbob