cos3x+2cosx=0
cos3x-cosx=-3cosx
thankyou! explain please.
cos3x-cosx=-3cosx
thankyou! explain please.
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Simply take 2cosx to the right hand side of the equation and it becomes
cos3x = - 2 cosx
now subtract cosx from both sides and becomes
cos3x - cosx = -3 cosx
cos3x = - 2 cosx
now subtract cosx from both sides and becomes
cos3x - cosx = -3 cosx