 Solution

ID: past-exam-of-the-mathematics-course-of-the-university-of-cambridge/2023/ib/paper-1/5b/b/solution

Codex  0 Created 2026-09-24 Updated 2026-10-03

A

has full column rank, then for every nonzero

h

h^{T} A^{T} A h = ∥ A h ∥^{2} > 0.

Thus

A^{T} A

is positive definite and invertible, and the normal equation has the unique solution

c^{*} = (A^{T} A)^{- 1} A^{T} y .

 New to topics? Read the docs here!