The angle made by the vecotr `vec(A)= hat(i)+hat(j)` with x-axis is

Options

A. `90^(@)`
B. `45^(@)`
C. `22.5^(@)`
D. `30^(@)`

Answer

B

Explanation

`vec(A) = A_(x) hat(i) + A_(y) hat(j) = (A cos alpha) hat(i) + (A sin alpha) hat(j)`
Since, `vec(A) = hat(i) + hat(j), cos alpha= (A_(x))/(A)= (1)/(sqrt(1^(2) + 1^(2))) = (1)/(sqrt2)`
`alpha= 45^(@)`