Ответы и объяснения

2012-05-26T12:14:53+00:00

=(sin²x-cos²y)(sin²x+cos²y)=(sin²x-1+sin²y)(sin²x+1-sin²y)=(sin²x+sin²y-1)(sin²x-sin²y+1)

 

sin²x-cos²y=sin²x+sin²y-1

 

 

(sin²x+sin²y-1)(sin²x-sin²y+1)=(sin²x+sin²y-1)

 

=> (sin²x-sin²y+1)=1

 

=>(sin²x+sin²y-1)*1=(sin²x+sin²y-1)  =>(sin²x+sin²y-1)=(sin²x+sin²y-1)