設(shè)y=y1+y2,y1與x成正比例,y2與x成反比例,并且當(dāng)x=1時,y1=1,y2=2,求當(dāng)x=3時函數(shù)y=y1+y2的值
設(shè)y1=k1x
y2=k2/x
當(dāng)x=1時,
y1=k1=1,
y2=k2=2
所以
y1=x
y2=1/x
當(dāng)x=3時函數(shù)y=y1+y2的值
y1=3
y2=1/3
y=y1+y2=3+(1/3)=10/3