Pre-Calc Course, Lec # 21 (Sum & Difference Formulas)

This is Lecture # 21 of the series of videos called "Pre-Calculus Course". This lecture discusses the Sum and Difference Formulas with several done examples like finding cos75 without using a calculator. At the end of each Pre-Calculus lecture, you find some (Old Exams Questions) to check your knowledge and practice more on that topic.

#findsin15 #findcos15 #findtan(u+v) #findcec(A+B)