x=20/y
(20/y)^2 + y^2=41
400/y^2+y^2=41
400+y^4=41y^2
y^2=t
t^2-41t+400=0
D=81
t1=(41+9)/2=25
t2=(41-9)/2=16
y^2=16
y^2=25
y=±4
y=±5
x=20/y
(20/y)^2 + y^2=41
400/y^2+y^2=41
400+y^4=41y^2
y^2=t
t^2-41t+400=0
D=81
t1=(41+9)/2=25
t2=(41-9)/2=16
y^2=16
y^2=25
y=±4
y=±5