functions and Hecke L-functions of an imaginary quadratic field,and various problems on elliptic modular forms. As to the values of Dirichlet L-functions, all previous papers and books reiterate a single old result with a single old method. After a review ofelementary Fourier analysis, the author presents completely new results with new methods. though old results will also be proved. No advanced knowledge of number theory is required up to this point. As applications, new formulas for the second factor ofthe class number of a cyclotomic field will be given. The second half of the book assumes familiarity with basic knowledge ofmodular forms. However,all definitions and facts are clearly stated, and precise references are given. The notion ofnearly holomorphic modular forms is introduced and applied to the determination of the critical values of Hecke L-functions of an imaginary quadratic field. Other notable features of the book are: (1) some new results on classical E