We know that the equation of the parabola is of the form y=ax²+bx+c in this problem y=1/4x²−x+3 where a=1/4 b=-1 c=3 the coordinates of the focus are (-b/2a,(1-D)/4a) where D is the discriminant b²-4ac D=(-1)²-4*(1/4)*3-----> D=1-3---> D=-2 therefore x coordinate of the focus -b/2a----> 1/[2*(-1/4)]----> 2
y coordinate of the focus (1-D)/4a------> (1+2)/(4/4)---> 3