Letu= <-1, 1, 2> andv= <2, -1, -1>. Findallunit vectors orthogonal tobothuandv.

I know that one can use cross products to find a vector orthgonal to bothuandvand scale it down to be a unit vector. But the question says to find all the unit vectors and I don't know how to go about doing that since there is an infinite number of them.