What is the cosine of the angle which the vector 
makes with y-axis?
The angle that a vector 
makes with y-axis is
In this question, a1=
, a2=1 and a3=1, Substituting in formulas we get
1
What is the cosine of the angle which the vector makes with y-axis?
The angle that a vector makes with y-axis is
In this question, a1=, a2=1 and a3=1, Substituting in formulas we get