hello Let's solve: (square root of 3)sin(x)-cos(x)=2 We know that R=square root of 3 + 1 = 2 We also know that tanφ=b/a= -1/sqrt3 The solution to tanφ=-1/sqrt3 has many solutions, for example, -30, 150, 330 degrees etc. Which of these solutions do we accept? Or is it irrelevant which we will accept? I mean, our equation will be this or that? this: 2sin(x-30)=2 => sin(x-30)=1 => x-30 = 2kπ + 90 or x-30 = 2kπ + π - 90 => x=2kπ+120 or x=2kπ+π-60 that: 2sin(x+330)=2 => sin(x+330)=1 => x+330 = 2kπ + 90 or x+330 = 2kπ + π - 90 => x=2kπ-240 or x=2kπ+π-420 which of these solutions are acceptable? thanks!