Trigonometry Lecture Series by Dr. Scott R. Franklin: Lecture 12: Identify the graphs the tangent, cotangent, cosecant and secant functions Purchase the Lecture Notes that accompany this lecture series: Trigonometry: Lecture Notes (Spiral Bound) - http://www.lulu.com/us/en/shop/scott-... Trigonometry: Lecture Notes (ebook) - http://www.lulu.com/us/en/shop/scott-...