any way. Thirdly, we note that a solution of equation(7)more general than (5)is 2兀 y(x)=Asin(x+o) (8) where o is a phase angle which can have any value. however we can remove this freedom by the specification that yo)=0 so that 2丌 Asin(0+o)=0 It follows that we may set equal to 0 as in the function (5).any way. Thirdly, we note that a solution of equation (7) more general than (5) is where  is a phase angle which can have any value. However, we can remove this freedom by the specification that y(0) = 0 so that It follows that we may set  equal to 0 as in the function (5)