Answer:
An arithmetic sequence is defined by:
[tex]a_n = a_{n-1} + d[/tex]
Here, we know that:
[tex]a_3 = 14\\a_{10} = 98[/tex]
Using the recursive relation, we can write:
[tex]a_{10} = 98 = a_9 + d[/tex]
And can keep applying the recursive relation, so we will have:
[tex]98 = a_9 + d = (a_8 + d) + d = a_8 + 2*d[/tex]
And so on, until we get to a known term:
[tex]98 = a_8 + 2*d = a_7 + 3*d = a_6 + 4*d = a_5 + 5*d = a_4 + 6*d = a_3 + 7*d[/tex]
[tex]98 = a_3 + 7*d = 14 + 7*d[/tex]
Then we can solve:
98 = 14 + 7*d
for d:
98 - 14 = 7*d
84 = 7*d
84/7 = d = 12
Now we know the value of d, we can keep using the recursive relation to find the first 3 terms:
Here, we can rewrite the recursive relation as:
[tex]a_{n-1} = a_n - d[/tex]
Then:
[tex]a_2 = a_3 - d = 14 - 12 = 2\\a_2 = 2[/tex]
[tex]a_1 = a_2 - d = 2 - 12 = -10\\a_1 = -10[/tex]
[tex]a_0 = a_1 - d = -10 - 12 = -22\\a_0 = -22[/tex]
Then the first 3 terms are:
-22, -10, 2
