given that x=120 sin (pi/12)t , what is the first time when the particle is (i) 30m to the right of the origin and (ii) 30m to the left of the origin?

Im thinking

30=120 sin (pi/12)t

1/4=sin (pi/12)t

t=(1/4) / sin (pi/12)

t=0.96592..... is this correct?

I don't know how tothinkabout the second part when x=-30. Is it more complicated or do I just solve it as above?

Thank you