这道平面向量坐标运算的题已知A(-2,4),B(3,-1),C(-3,4)设 AB= a,BC= b ,CA= c求 3a + b - 3c;这一题解出来是:∵A(-2,4),B(3,-1),C(-3,4)∴ a = AB = (5,-5)b = BC = (-6,-3)C = CA = (1,8)最后3个坐标
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![这道平面向量坐标运算的题已知A(-2,4),B(3,-1),C(-3,4)设 AB= a,BC= b ,CA= c求 3a + b - 3c;这一题解出来是:∵A(-2,4),B(3,-1),C(-3,4)∴ a = AB = (5,-5)b = BC = (-6,-3)C = CA = (1,8)最后3个坐标](/uploads/image/z/1124586-18-6.jpg?t=%E8%BF%99%E9%81%93%E5%B9%B3%E9%9D%A2%E5%90%91%E9%87%8F%E5%9D%90%E6%A0%87%E8%BF%90%E7%AE%97%E7%9A%84%E9%A2%98%E5%B7%B2%E7%9F%A5A%EF%BC%88-2%2C4%EF%BC%89%2CB%EF%BC%883%2C-1%EF%BC%89%2CC%EF%BC%88-3%2C4%EF%BC%89%E8%AE%BE+AB%3D+a%2CBC%3D+b+%2CCA%3D+c%E6%B1%82+3a+%2B+b+-+3c%EF%BC%9B%E8%BF%99%E4%B8%80%E9%A2%98%E8%A7%A3%E5%87%BA%E6%9D%A5%E6%98%AF%EF%BC%9A%E2%88%B5A%EF%BC%88-2%2C4%EF%BC%89%2CB%EF%BC%883%2C-1%EF%BC%89%2CC%EF%BC%88-3%2C4%EF%BC%89%E2%88%B4+a+%3D+AB+%3D+%EF%BC%885%2C-5%EF%BC%89b+%3D+BC+%3D+%28-6%2C-3%29C+%3D+CA+%3D+%281%2C8%29%E6%9C%80%E5%90%8E3%E4%B8%AA%E5%9D%90%E6%A0%87)
这道平面向量坐标运算的题已知A(-2,4),B(3,-1),C(-3,4)设 AB= a,BC= b ,CA= c求 3a + b - 3c;这一题解出来是:∵A(-2,4),B(3,-1),C(-3,4)∴ a = AB = (5,-5)b = BC = (-6,-3)C = CA = (1,8)最后3个坐标
这道平面向量坐标运算的题
已知A(-2,4),B(3,-1),C(-3,4)
设 AB= a,BC= b ,CA= c
求 3a + b - 3c;
这一题解出来是:∵A(-2,4),B(3,-1),C(-3,4)
∴ a = AB = (5,-5)
b = BC = (-6,-3)
C = CA = (1,8)
最后3个坐标怎么计算的?是用终点坐标减起点坐标吗?我计算怎么算的和答案不一样?
这道平面向量坐标运算的题已知A(-2,4),B(3,-1),C(-3,4)设 AB= a,BC= b ,CA= c求 3a + b - 3c;这一题解出来是:∵A(-2,4),B(3,-1),C(-3,4)∴ a = AB = (5,-5)b = BC = (-6,-3)C = CA = (1,8)最后3个坐标
如果你题目没抄错的话,答案确实是错了.a的计算结果是正确的,b=(-6,5),c=(-1,0).估计是题目有个负号标错位置了.平面直角坐标系的向量计算方法确实是终点坐标减去起点坐标
b和c算错了. b=(-6,5) c=(-1,0)
3a=3*(15,-15) 3c=(-3,0)
∴3a+b-3c=(15-6+3,-15+5-0)=(12,-10)
这道题目的答案不是坐标,是一个数字