已知x、y满足x²+y²-6x+2y+10=0,求³√(x²-y²)的值.
问题描述:
已知x、y满足x²+y²-6x+2y+10=0,求³√(x²-y²)的值.
答
x²+y²-6x+2y+10=0
→(x-3)^2+(y+1)^2=0
→x=3,y=-1
3√(x^2-y^2)=3√(9-1)=2
不懂, 请追问,祝愉快O(∩_∩)O~
答
x²+y²-6x+2y+10=0
(x²-6x+9)+(y²+2y+1)=0
(x-3)²+(y+1)²=0
∵(x-3)²≥0,(y+1)²≥0
∴x-3=0,y+1=0
∴x=3,y=-1
∴³√(x²-y²)=³√[3²-(-1)²]=³√8=2