设y1=k*根号x,y2=m/(x-3).
x=4时,y=3.代入得2*k+m=3 (1)
x=1时,y=3.代入得k-m/2=3 (2)
(1)+2*(2)得4*k=9,k=9/4
代入(1),得m=3-2*k=-3/2
于是当x=9时,y=3*k+m/6=27/4-1/4=13/2
设y1=k*根号x,y2=m/(x-3).
x=4时,y=3.代入得2*k+m=3 (1)
x=1时,y=3.代入得k-m/2=3 (2)
(1)+2*(2)得4*k=9,k=9/4
代入(1),得m=3-2*k=-3/2
于是当x=9时,y=3*k+m/6=27/4-1/4=13/2