Question

Cos(120°+x)-cos(x)=sin(x+240°)

Answer 1

Answer:

hiiii friend,

cosx + cos (120-x) + cos (120+x)

=>. cosx + 2cos [(120-x+120+x) /2] cos [(120-x-120-x) /2]

=>. cosx + 2cos120 cos(-x)

=>. cosx + 2cos(180-60) cosx

=>. cosx + 2 (-cos 60) cosx

=>. cosx - 2 × 1/2 cosx

=>. cosx - cosx

=>. 0 hence proved....

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Step-by-step explanation: