Analysis: Let the slope (derivative) of any point on A(x 1, y 1)B(x2, y2) and curve x 2 = 2py be y'=x/p, then the tangent equation of A and B can be easily obtained: y = (x1/p. The coordinate of the intersection of the solutions of simultaneous equations, that is, the m coordinate x =( 1AB slope k = (y1-y2)/(x1-x2) = (x1+x2). So the chord length AB can be expressed as | AB | = (1+k2) 0.5 [(x1+x2) 2-k, x1+x2] 0.5 = 4 *10.5, k, x/kloc. The substitution of the value of x 1x2 is simplified as (1+4/p2) (1+p2) =10, and the solution is p 2 = 1, so p = (+-) 65438+ I hope everyone can adopt it. Ha ha! ?