Hey students!!! ‍ ‍
You will learn the proof of a very important trigonometry formula (identity)
cos(x y) = cosx cosy + sinx siny
in a very easy and simple way.

The formula is one of the basic formulas that is used to derive many more trigonometric formulas. So it becomes extremely important for students to understand the underlying concepts as well.

This formula can be treated as a special case of formula of cos(x + y) which we have already learnt here:    • Prove that  cos (x + y) = cosx cosy ...  

#trigonometry #class11maths #class11mathsolution #trigonometricfunctions #trigonometricformula #cosformula #mathsbysunilsir #mathsbysunilsyal #mathemafia #trigonometricidentities

Prove that cos(a b) = cosa cosb + sina sinb

Website: https://www.mathemafia.com/
Subscribe:    / @mathemafia  
Facebook: https://www.facebook.com/Mathemafia1...