Plzzz help me on this question
This is Additional mathematics IGCSE

Answer:
[tex] \alpha = 7[/tex]
Step-by-step explanation:
[tex]a(vector) = 4i - 2j[/tex]
[tex]b(vector) = \alpha i + 2j[/tex]
[tex]ab(vector) = ( \alpha - 4)i \: + 4j[/tex]
Now,
Let K * ab (unit vector) = ab (vector)
Solving further :
[tex] \alpha = 7[/tex]