已知正数x,y,z满足x+2y+3z=1,则(1/(x+2y))+(4/(2y+3z))+(9/(3z+x))的最小值为?

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已知正数x,y,z满足x+2y+3z=1,则(1/(x+2y))+(4/(2y+3z))+(9/(3z+x))的最小值为?已知正数x,y,z满足x+2y+3z=1,则(1/(x+2y))+(4/(2y

已知正数x,y,z满足x+2y+3z=1,则(1/(x+2y))+(4/(2y+3z))+(9/(3z+x))的最小值为?
已知正数x,y,z满足x+2y+3z=1,则(1/(x+2y))+(4/(2y+3z))+(9/(3z+x))的最小值为?

已知正数x,y,z满足x+2y+3z=1,则(1/(x+2y))+(4/(2y+3z))+(9/(3z+x))的最小值为?

需要用柯西不等式

[(x+2y)+(2y+3z)+(3z+x)][1/(x+2y)+4/(2y+3z)+9/(3z+x)]≥(1+2+3)²
∴1/(x+2y)+4/(2y+3z)+9/(3z+x)
≥36/[2(x+2y+3z)]
=18.
最小值=18

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