x+y>0 y-3《0,x-y-1《0,则根号（x^2+y^2)的max是?

x+y>0 y-3《0,x-y-1《0,则根号（x^2+y^2)的max是?
x+y>0 y-3《0,x-y-1《0,则根号（x^2+y^2)的max是?

x+y>0 y-3《0,x-y-1《0,则根号（x^2+y^2)的max是?
求√(x^2 + y^2)的最大值
√(x^2 + y^2)=√[(x-0)^2 + (y-0)^2]
即(x,y)到(0,0)距离的最大值
x+y>0 y-3《0,x-y-1《0
作图,线性回归
易知,直线x-y-1=0与y=3的交点是x,y两个值最大的时候,交点为(4,3)
则√(x^2 + y^2)最大值为5

y-3<0,y<3
x+y>0
x-y-1<0
-y-3x^2+y^2<25