When t=0, x=0, v=V
x = asin(nt)
v= ancos(nt)
When t=0, v=V
V= an
a= V/n
Rewriting the v and x functions, we get
x = V/n * sin(t)
v = Vcos(nt)
For v to equal 0;
0=Vcos(nt)
nt = pi/2
t = pi/2n
The displacement at that time = V/n * sin(n * pi/2n)
Hence distance = V/n