fiitjee aits RTPF 2

Figure shows a YDSE set-up. The source (0,0) of wavelength 4000 A oscillates along y-axis according the the equation y=sin(pi)t where y is in millimetres and t is in seconds. The distance between two slits S1 and S2 is 0.5mm.

1) The instant at which maximum intensity occurs at P for the first time?

2) The instant at which minimum intensity occurs at P for the first time?

3) The position of the central maxima as a function of time is?

Ans :
1) 1/pi sin inv (59/80)
2) 1/pi sin inv (27/80)
3) -4sin(pi)t

Please show your working.