2 (25 points) Let n be a natural number and the real vector space Vn be defined by 1 Vn = span{ Cos x, sin x, cos 2x, si
Posted: Wed May 11, 2022 10:59 pm
2 (25 points) Let n be a natural number and the real vector space Vn be defined by 1 Vn = span{ Cos x, sin x, cos 2x, sin 2x, ... , COS nr, sin nx}. COS X V2 Show that if şr(x) is the n-th partial sum of the Fourier series of a real square- for integrable function f(x), - < x < 77, then a - || Sn(x) – f(x)|| < ||Pn(2) – f(x)|| for all pn € Vng where ||g|| = VAS A \g(x) dx . TT -