The projection of `OvecP` on a unit vector `OvecQ` equals thrice the area of parallelogram OPRQ. Then `|__` POQ is
tan`-`1 `((1)/3)`
cos`-`1 `((3)/10)`
sin`-`1 `((3)/sqrt(10))` ``
sin`-`1 `((1)/3)`
how can i solve this