PROBLEMS, SECTION 9 The functions in Problems 1 to 3 are neither even nor odd. Write each of them as the sum of an even function and an odd function. 1. (a) em\" (b) me"2 2. (a) lnllm (b) (l+:t:)(sin:r+cosa:) m (b) 1+er 4. Using what you know about even and odd functions, prove the rst part of (5.2). Each of the functions in Problems 5 to 12 is given over one period. For each function, sketch several periods and decide whether it is even or odd. Then use (9.4) or (9.5) to expand it in an appropriate Fourier series. 5. f(:n)={_1' 7r<:r x _ . answer: t sin and>