The angle θ between the vector p=i^+j^+k^ and unit vector along X-axis is
cos-113
cos-112
cos-132
The angle between, p=i^+j^+k^
and X-axis, x = i^ is given by
cosθ=p·x|p||x|=(i^+j^+k^)·(i^)12+12+12·12=13
∴ θ = cos-113