已知函數(shù)f(x)=x-p/x(x>1)若函數(shù)f(x)是增函數(shù),求實(shí)數(shù)p的范圍解關(guān)于x的不等式f(x)
已知函數(shù)f(x)=x-p/x(x>1)若函數(shù)f(x)是增函數(shù),求實(shí)數(shù)p的范圍解關(guān)于x的不等式f(x)
優(yōu)質(zhì)解答
f(x)=x-p/x<2
x-p/x-2<0
(x^2-2x-p)/x<0
[(x-1)^2-1-p]/x<0
[x-(1+根號(hào)(1+p)][x-(1-根號(hào)(1+p)]/x<0
因?yàn)閜>=1,則1+根號(hào)(1+p)>0,1-根號(hào)(1+p)<0
故解集是:x<1-根號(hào)(1+p)或0