3cos x = sin(x+60°), for 0° ≤ θ ≤ 360°

sin(A + B) = sinAcosB + cosAsinB

=> sin(x + 60°) = sinxcos60° + cosxsin60°

=> (1/2)sinx + (√3/2)cosx

=> 3cosx = (1/2)sinx + (√3/2)cosx

i.e. 6cosx = sinx + (√3)cosx

so, (6 - √3)cosx = sinx

=> tanx = 6 - √3

=> x = 76.8° + 180n°....for n = 0, 1, 2,...

i.e. x = 76.8° and 256.8° in the range 0° ≤ x ≤ 360°

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