145 points 20 12? Chongqing? Make a straight line through the focus f of the parabola y2=2x, and cross the parabola at a? Two o'clock? What if? And then |AF|=? Test center? Simple properties of parabola.

Analysis? Establish an equation between the coordinates of a point and the coordinates of a straight line? Use the definition of parabola to express |AF|, |BF| and then combine the equations of straight line and parabola to solve the problem by using the relationship between roots and coefficients? You can get the answer. Answer? Solution? Can you get it from the meaning of the question? Set F 0 to a? x 1？ y 1B？ x2？ Y2 makes a straight line L through the focus F of parabola y2=2x, and intersects with parabola at points A and B? So |AF|= +x 1? |BF|= +x2？ Because? So x 1+x2= Let the equation of straight line L be y=k? x？ Can we get the simultaneous equation of straight line and parabola? k2x2k2+2？ x+ =0？ So x 1+x2=? ∴ ∴k2=24 ∴24x2？ 26x+6=0？ ∴ ? ∴|AF|= +x 1= So the answer is? 5/6