d
\({{\text{R}}_{\text{1}}}{\text{  =  }}{{\text{R}}_{\text{1}}}^{\text{0}}{\text{(1  +  }}{\alpha _{\text{1}}}{{\text{t}}_{\text{1}}}{\text{) ; }}\)

\({{\text{R}}_{\text{2}}}{\text{  =  }}{{\text{R}}_{\text{2}}}^{\text{0}}{\text{(1  +  }}{\alpha _{\text{2}}}{{\text{t}}_{\text{2}}}{\text{) }}\)

માટે \({{\text{R}}_{\text{1}}}{\text{  =  }}{{\text{R}}_{\text{2}}}\) અને \({{R}_{1}}^{0}={{R}_{2}}^{0},\)

\(\therefore \,\,\frac{{{R_1}}}{{{R_2}}}\,\, = \,\,\frac{{(1\, + \,{\alpha _1}{t_1})}}{{(1\, + \,{\alpha _2}{t_2})}}\,\, = \,\,1\)

\(\therefore \,\,\,1\, + \,{\alpha _1}\,{t_1}\,\, = \,\,1\, + \,{\alpha _2}\,{t_2}\, \Rightarrow \,\frac{{{\alpha _1}}}{{{\alpha _2}}}\,\, = \,\,\frac{{{t_2}}}{{{t_1}}}.\)