文[1]的解答是错误的,《教师用书》的答案是正确的,理由如下:1课本定义的正确理解设e_1,e_2,e_3为有公共起点O的三个两两垂直的单位向量(我们称它们为单位正交基底),以e_1,e_2,e_3的公共起点O为原点,分别以e_1,e_2,e_3的方向为x轴,y轴,z轴的正方向建立空间直角坐标系 The answer to the paper [1] is wrong. The answer to “Teacher’s Book” is correct for the following reasons: 1 Correct understanding of the textbook definition Let e_1, e_2 and e_3 be three two-by-two vertical unit vectors with common starting point O We call them orthonormal base of unit), take the common starting point O of e_1, e_2, e_3 as the origin, and establish the rectangular Cartesian coordinate system in the positive direction of x axis, y axis and z axis respectively in the direction of e_1, e_2, e_3