Find the angle of vector ` vec a` = 6` hat i` + 2` hat j` - 3` hat k` with `x` -axis.

Explanation

`" "veca=6hati+2hatj-3hatk`
or `" "|veca|=sqrt((6)^(2)+(2)^(2)+(-3)^(2))=7`
Hence, the angle of vector with the `x`-axis is `cos^(-1)""(6)/(7)`.