Question

***6.If cosa + cosB + cos y = 0 = sin a + sinſ + sin y
then show that
i) cos 3a + cos 3B + cos 3y = 3 cos(a + B + y)
ii) sin 3a + sin 3B +sin 3y = 3 sin(a +B+ y)
iii) cos(a +B) + cos(B + y) + cos(y+a)= 0
answer it in a detailed way
if Ur answer is correct i will mark your answer as the brainliest ​

Answer 1

|| ★★ FORMULA AND CONCEPT USED ★★ ||

☛ DE-Moievere's theorem says that [cosA + i*sinA]ⁿ = [cos(nA) + i*sin(nA) ] ...

☛ if (x + y + z) = 0,, then (x³ + y³ + z³) = 3xyz..

☛ Complex Number Theorem :- When n complex numbers are multiplies, then its modulus is product of their modulii and amplitude is sum of their amplitudes...

☙☘ Refer To Image Now.. ☙☘

Answer 2

Step-by-step explanation:

hope this answer will help you