Question

Cos2 alpha + cos 2 beta + cos 2 gama =??

Answer 1

Answer:

0

Explanation:

cos  

2

xα+cos  

2

β+cos  

2

γ+1=0

asweknow

cos2A=2cos  

2

A−1

cos  

2

α+cos  

2

β+cos  

2

γ=1

now,

LHS

cos  

2

α+ci=cos  

2

β+cos  

2

γ+1

2cos  

2

α−1+2cos  

2

β−1+2cos  

2

γ−1+1

2(cos  

2

α+cos  

2

β+cos  

2

γ)−3+1

2×1−2

2−2

0henceproved.

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