若x-1=(y+1)/2=9z-2)/3,則x方+y方+z方的最小值是
若x-1=(y+1)/2=9z-2)/3,則x方+y方+z方的最小值是
其他人氣：767 ℃時(shí)間：2020-08-30 21:27:43
優(yōu)質(zhì)解答
x-1=(y+1)/2y+1=2x-2y=2x-3x-1=(9z-2)/39z-2=3x-3z=(3x-1)/9=x/3-1/9所以x^2+y^2+z^2=x^2+(2x-3)^2+(x/3-1/9)^2=x^2+4x^2-12x+9+x^2/9-2x/27+1/81=(46/9)x^2-(326/27)x+730/81=(46/9)(x-163/138)^2+779/414所以最小...
我來回答
類似推薦
- x+4y+9z=1,求x^2+y^2+z^2的最小值
- 設(shè)x，y∈R，且x+y=3，則2x+2y的最小值為（ ?。?A.6 B.42 C.23 D.26
- 已知點(diǎn)A(x,y)在拋物線y方=4x上運(yùn)動(dòng),求z=x方+y方/2+3的最小值.
- 當(dāng)x,y,z>0時(shí)x+2y+3z=1u=x*x/(x+1)+4y*ysup2/(2y+1)+9z*z/(3z+1)的最小值
- 二次函數(shù)y=3(X-2)方+7的最小值是
- 函數(shù)f(x)=sinx-cosx^2的最小值是?
- 英語翻譯
- I took my grandpa to the hospital this morning,_____ I missed the first class.
- So crazy
- 方差是各個(gè)數(shù)據(jù)與平均數(shù)之差的平方的平均數(shù)
- 函數(shù)y=f(x)與它反函數(shù)y=f^-1(x)怎么讀?
- These are photos of my families.Look at them 改錯(cuò)
猜你喜歡
- 1平面與平面重合,是否屬于平行一類?那重合的兩直線,也屬于平行一類的嗎?
- 2非洲每年因饑餓死亡的人數(shù)及現(xiàn)在饑餓人口數(shù)量拜托各位了 3Q
- 3decide to do sth.還=什么
- 4(7/8)o you think of london?B:5.____london is one of the liveliest cities
- 5啤酒可以托運(yùn)嗎
- 6邊長為2√6的等邊三角形的中心到一邊的距離為?
- 7please give your hand to help me
- 8已知2的X次方等于3的Y次方等于6的Z次方不等等于1,證明X分之一加Y分之一等于Z分之一.
- 9幫我做做?
- 10機(jī)械分析天平TG628A的使用說明書
- 11in winter ,we wear warm coats to protect our bodies_.
- 12( )was most importance to her ,she told me,was her family it this what as