Question

prove cos(a-b)=cosacosb+sinasinb

Answer 1

Answer:

$\huge\bigstar\huge\tt\underline\red{ᴀɴsᴡᴇʀ }\bigstar$

• Equal chords of a circle substends equal angle at the centre
• as both angles are same at center so their chords are also equal
• By using distance formula:-

last step:- squaring both sides and we find out the value of :-

at last we diving both sides by -2

Hope it helps you..!!!