Substitution of solution into formula?

Questions
1

How to automatically, not manually, insert the output values a1 and k1 of Out[3] as starting values of a2 and k2 in In[6]?

In[1]:= data1 = {{1.0, 12.}, {1.9, 10.}, {2.6, 8.2}, {3.4, 6.9}, {5.0, 5.9}};

In[2]:= model1 = a1 Exp[-k1 t];

In[3]:= fit = FindFit[data1, model1, {a1, k1}, t]

Out[3]= {a1 -> 14.3889, k1 -> 0.198208}

In[4]:= data2 = {{1.1, 11.9}, {1.8, 11.}, {2.7, 8.4}, {3.3, 6.7}, {4.9, 6.1}};

In[5]:= model2 = 1 + a2 Exp[-k2 t];

In[6]:= FindFit[data2, model2, {{a2, 14.3889}, {k2, 0.198208}}, t]

Out[6]= {a2 -> 14.3473, k2 -> 0.236929}

Example.nb (7.26 KB)

2

Hi Eduardo,

Here is one way

FindFit[data2, model2, {{a2, a1 /. fit}, {k2, k1 /. fit}}, t]
3

Thank you very much.

What if the values of “a” are 100 and the values of “k” are 100, say?
That is, a1, …, a100, k1, …, k100.

4

I apologize. I misspelled.
(a1)1,…, (a1)100,
(k1)1,…,(k1)100,
(a2)1,…, (a2)100,
(k2)1,…,(k2)100.