Verified answer

Answer:

A=B=60∘

we know that

sin60∘=23,sin30∘=21

(i) cos(A−B)=cosAcosB+sinAsinB

cos(60−60)=cos60cos60+sin60sin60

cos(0)=cos260+sin260

1=(21)2

hope it's helpful army

have bangtan day ahead

I hope it will be help you.