Question

What are the components of the vector between the origin and the polar coordinate `(2, (19pi)/12)`?

Answer 1

`=>vecA=2cos(5pi/12)hati-2sin(5pi/12)hatj`

Explanation:

If polar coordinate of a position vector `vecA` w.r.t origin is `(r,theta)` then `vecA=rcosthetahati+rsinthetahatj`
In our problem `r=2 andtheta =19pi/12`

so `vecA=2cos(19pi/12)hati+2sin(19pi/12)hatj`
`=>vecA=2cos(2pi-5pi/12)hati+2sin(2pi-5pi/12)hatj`
`=>vecA=2cos(5pi/12)hati-2sin(5pi/12)hatj`