已知实数xy满足等式3x²+2y²-6x=0,求w=x²+y²的取值范围
问题描述:
已知实数xy满足等式3x²+2y²-6x=0,求w=x²+y²的取值范围
答
3x²+2y²-6x=0y² = -3/2x²+3x = -3/2x(x-2) ≥ 00≤x≤2w = x²+y² = x²-3/2x²+3x = -1/2x²+3x =-1/2(x-3)²+9/20≤x≤2-3≤x-3≤11≤(x-3)²≤9-9/2≤-1/2(x-3...