What is the equation of this parabola?

x+1=1/4(y-3)^2
x-1=1/4(y-3)^2
x+1= -1/4 (y-3)^2
x-1= - 1/4)y-3)^2

Two cities a and b are 1400km apart and lie on the same n-s line. the latitude of city a is 23 degrees. what is the latitude of city b. the radius of the earth is approximately 6400km.