问题详情
已知二次型f(x1,x2,x3,x4)=2x1x2+2x1x3+2x1x4+2x3x4,则二次型f(x1,x2,x3,x4)的矩阵为_______,二次型f(x1,x2,x3,x4)的秩为________.
请帮忙给出正确答案和分析,谢谢!