Question

反比例函数的计算1.已知函数y=y1+y2,其中y1,y2都是X的函数,y1与X^2成正比例,y2与1-X成反比例,且当

Answer 1

(1)设 y1=k1x^2 y2=k2/(1-x)

when x=2

-8=4k1

-8=-k2

so k1=-2 k2=8

so y=-2x^2+8/(1-x)

(2) 设 y1=k1#x y2=k2/x^2

so y=k1#x-k2/x^2

when x=1 0=k1-k2

when x=2 31/4=k1#2-k2/4

so k1=k2

(4#2-1)k1=31

so k1=31/(4#2-1)=[31*(4#2+1)]/[(4#2-1)(4#2+1)]

=31(4#2+1)/31=4#2+1

so y=(4#2+1)#2-(4#2+1)/x^2