\(f\left( x \right)={{a}_{0}}+\mathop{\sum }_{{n=1}}^{\infty }\left( {{{a}_{n}}\cos \frac{{n\pi x}}{L}+{{b}_{n}}\sin \frac{{n\pi x}}{L}} \right)\)

1) \(\left( x \right)={{a}_{0}}+\mathop{\sum }_{{n=1}}^{\infty }\left( {{{a}_{n}}\cos \frac{{n\pi x}}{L}+{{b}_{n}}\sin \frac{{n\pi x}}{L}} \right)\)   2) The lines represented by the equation \(\displaystyle 2x{{\,}^{2}}\,+\,\,5\,xy\,+\,\,2\,y{{\,}^{2}}\,=\,0\)are   3)The lines represented by the equation \(\displaystyle …