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)
Gayathri , 6 Years ago
Grade 11
Trigonometry> Cos alpha+cos beta=0=sin alpha +sin beta ...
1 AnswersSiddhartha reddy
Last Activity: 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
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