Question

Plzzz help me on this question
This is Additional mathematics IGCSE ​

Answer 1

`\alpha = 7`

Explanation:

`a(vector) = 4i - 2j`

`b(vector) = \alpha i + 2j`

`ab(vector) = ( \alpha - 4)i \: + 4j`

Now,

Let K * ab (unit vector) = ab (vector)

1. (0.4 * k) j = 4 j Thus, K = 10
2. 
   `(0.3 * k)i = ( \alpha - 4)i`

Solving further :

`\alpha = 7`