Given that the parabola y ^ 2 = 4x, the points P (1,2), a (x1, Y1), B (X2, Y2) are on the parabola, when the slopes of PA and Pb exist and the inclination angles complement each other, we can find the solution Find the value of Y1 + Y2 and the slope of line ab

Given that the parabola y ^ 2 = 4x, the points P (1,2), a (x1, Y1), B (X2, Y2) are on the parabola, when the slopes of PA and Pb exist and the inclination angles complement each other, we can find the solution Find the value of Y1 + Y2 and the slope of line ab

(1) KPa = y1-2 / x1-1 = y1-2 / (Y1 ^ 2 / 4-1) = 4 (y1-2) / (Y1 ^ 2-4) = 4 / (Y1 + 2) KPB = y2-2 / x2-1 = y2-2 / (Y2 ^ 2 / 4-1) = 4 (y2-2) / (Y2 ^ 2-4) = 4 / (Y2 + 2)