Linear Algebra and Its Applications · Problem 3.2.19

Orthogonality — Gilbert Strang

Mathematics · cosines-projections-onto-lines

Problem

In Problem 17, find the projection matrix

P = aa^T/a^Ta

onto the line through each vector

a

. Verify in both cases that

P^2 = P

. Multiply

Pb

in each case to compute the projection

p