Let P(x,y) be any point on parabola focus is S(6,2) let M be the foot of perpendicular from P on directrix y=1 or y-1=0 then SP=PM
squaring both sides (x-6)^2+(y-2)^2=(y-1)^2 x^2-12x+36+y^2-4y+4=y^2-2y+1 x^2-12x+40=y^2-2y+1-y^2+4y x^2-12x+40=2y+1 or 2y=x^2-12x+39 which eq of parabola
As the directrix is parallel to x-axis, the concavity of the parabola will be in vertical. Then, the general equation is in the form: , where are the coordinates of the vertice and p is the parameter (distance between the focus and the directrix). The parameter is . The vertice is the midpoint between the focus and the projection of the focus in the directrix. Then, the vertice is . Hence, the parabola is:
Now, derivating:
The answer is -10 and -13. when added they equal -23 and when you switch the symbol of the 10 and make the equation 10-13 you get -3. hope this helped.