My working out:
Vector AB = b - a
let b be = xi + yj
Vector AB = (x + 2)i +(y - 6)j
Vector AC = c - a
= (1 - (-2))i + (3-6)j
= 3i - 3j
I know to prove vector AB and vector AC are perpendicular to each other, their scalar product has to be zero so I have found 3(x + 2) - 3(y - 6) = 0 How do I continue from here?
can someone please show me a way to solve this problem?
Answers from textbook:
