SOLUTION: Find the general solution of 3cos(x) + sin(x) = 0

Our starting equation is

    3cos(x) + sin(x) = 0


It is equivalent to 

    sin(x) = - 3cos(x).


Since cos(x) is not the solution to this equation, we can divide both sides by cos(x) safely,
without loosing the solutions.  It gives the equivalent equation

     = -3,

or

    tan(x) = -3.


The general solution to this equation is  x =  =   radians.    ANSWER