Guest

Cos alpha+cos beta=0=sin alpha +sin beta then find cos (alpha-beta)

Cos alpha+cos beta=0=sin alpha +sin beta then find cos (alpha-beta)

Grade:11

1 Answers

Siddhartha reddy
13 Points
6 years ago
Given,
Cos alpha + cos beta = 0, cos alpha = -cos beta
Sin alpha + sin beta = 0, sin alpha = -sin beta
Cos(alpha-beta) = cos alpha × cos beta + sin alpha × sin beta
= - cos beta × cos beta + (-sin beta ) × sin beta
= -cos^2 beta - sin^2 beta 
=-(cos^2 beta + sin^2 beta)
=-(1)
=-1

Think You Can Provide A Better Answer ?

ASK QUESTION

Get your questions answered by the expert for free