Consider the vectors and a general vector .
Write an equation in terms of , , and that describes all the vectors orthogonal to .
Write a linear system that describes all the vectors orthogonal to both and .
Write the solution set to this linear system in parametric form. What type of geometric object does this solution set represent? Indicate with a rough sketch why this makes sense.
Give a parametric description of all vectors orthogonal to . What type of geometric object does this represent? Indicate with a rough sketch why this makes sense.
Austin, Understanding Linear Algebra, §6.1 The dot product, Exercise 6