What is the equation of the normal to x2=4yx^2 = 4yx2=4y at (2,1)(2, 1)(2,1)?
x+y=3x + y = 3x+y=3
x−y=1x - y = 1x−y=1
x+y=1x + y = 1x+y=1
2x+y=52x + y = 52x+y=5