Question

if cos (a+b)=0 cos B=root 3/2 find a​

Answer 1

Answer:

cos(A−B)=1⟹A−B=2nπ

cosB=3–√2⟹B=2mπ±π6=(12m±1)π6

∴(A+B)=(A−B)+(2B)=2nπ+(12m±1)π3

=[6(2m+n)±1]π3=(6k±1)π3