lc=2abcosy/2/a+b выразите cosy/2

Question

lc=2abcosy/2/a+b выразите cosy/2

Answer 1

lc=2abcosy/2/a+b <=> 2abcosy/2/a=lc-b <=> cosy/2/a=(lc-b)/(2ab) <=> cosy/2=a*(lc-b)/(2ab)