Question:

Let f<span class="math-inline">(x) = \frac{\sin \{x\}}{x^2 + ax + b} . If f<span class="math-inline">(5*)</span> & f<span class="math-inline">(3*)</span> exists finitely and are not zero, then the value of (a + b) is (where { . } represents fractional part function) -