MathDB
f(x)=g(x)sin+h(x)cos with continuous functions

Source: VJIMC 1995 2.3

November 25, 2021
functioncontinuousreal analysis

Problem Statement

Let f:RRf:\mathbb R\to\mathbb R be a continuous function. Do there exist continuous functions g:RRg:\mathbb R\to\mathbb R and h:RRh:\mathbb R\to\mathbb R such that f(x)=g(x)sinx+h(x)cosxf(x)=g(x)\sin x+h(x)\cos x holds for every xRx\in\mathbb R?