(1)先求出和的坐标,然后利用向量垂直的坐标表示建立关于k的方程,求k即可. (2)先求出和的坐标,然后利用向量平行的坐标表示建立关于k的方程,求k即可. (1)k+ =" k(1,2)" + (-3,2) = (k-3,2k + 2),-3= (1,2)-3(-3,2) = (10,-4) (1) (k+ )⊥(-3),得 (k+ )·(-3) = 10(k-3)-4(2k + 2) = 2k-38 =" 0," k = 19 ; (2) (k+ )//(-3),得 -4(k-3) =" 10(2k" + 2), ……9分 k = - |