using the distance formula..
8=sqrt (3^2 + y^2)
square bot sides.
64=9+y^2
subtract 9 from both sides
55=y^2
y=sqrt 55
find y so that the distance between the points is 8:
(0,0) (3,y)
2 answers
The distance formula is just the pythagorean theorem(x^2+y^2=hypotenuse^2). If you know x (0+3=3) and you know the hypotenuse (8), you can find y.
3^2 + y^2 = 8^2
9 + y^2 = 64
y^2 = 55
y = sqrt(55)
3^2 + y^2 = 8^2
9 + y^2 = 64
y^2 = 55
y = sqrt(55)