If x is positive what is the least value of x+16/x

If x is positive what is the least value of x+16/x
If x is positive what is the least value of x+16/x

If x is positive what is the least value of x+16/x
如果x是正数,求x+16/x的最小值.
x+16/x
≥2×√x × √(16/x)
=2×4
=8 当且仅当√x= √(16/x),x=4时取等
所以,x=4时,x+16/x取最小值8