Given the vector a = (1,2), the vector b = (- 2, n), the angle between the vectors a and B is 45 °, find the vector B. if the vectors C and B are in the same direction, C-A ⊥ a, find C

Given the vector a = (1,2), the vector b = (- 2, n), the angle between the vectors a and B is 45 °, find the vector B. if the vectors C and B are in the same direction, C-A ⊥ a, find C

The vector a = (1,2), the vector b = (- 2, n), the angle between the vectors a and B is 45 °, cos45 ° = (- 2 + 2n) / (√ 5 × √ (4 + n & sup2;)) √ 2 / 2 = (- 2 + 2n) / (√ 5 × √ (4 + n & sup2;)) and the solution is n = 6 or n = - 2 / 3. The vector b = (- 2,6) or B = (- 2, - 2 / 3). Let the vector C = (x, y) ⊥ C-A = ⊥ a (...)