实数x,y满足3x^2+2y^2=6x,求x^2+y^2的最小值和最大值高中参数方程过程

问题描述:

实数x,y满足3x^2+2y^2=6x,求x^2+y^2的最小值和最大值高中参数方程过程

3x^2+2y^2=6x3x^2-6x+3+2y^2=33(x-1)^2+2y^2=3(x-1)^2+(2/3)y^2=1令x-1=sina y=√(3/2)cosax^2+y^2=(1+sina)^2+(3/2)(cosa)^2=(sina)^2+2sina+1+(cosa)^2+(1/2)[1-(sina)^2]=-(sina)^2/2+2sina+5/2=(-1/2)[(sina)^2-...