**3. Stability Analysis**

This section is used to show our main results. First, let us denote *bi* = max *r*∈[0,*T*] *f*(*r*) + *Bi* for *i* = 0, 1, 2 and *c* = *C*. In the next subsections, we study the FTS of (2) when *λ*<sup>1</sup> < *λ*<sup>2</sup> and when *λ*<sup>1</sup> = *λ*2.
