Answer:
The correct answer option is: 19, 13, 3, -11, -29.
Step-by-step explanation:
We are given the following explicit formula for an arithmetic sequence:
[tex]a_n=21-2n^2[/tex]
So to find the first five terms of this sequence, we will substitute the values of [tex]n[/tex] (num here in the given formula:
[tex]a_1=21-2(1)^2\\\\a_1=19[/tex]
[tex]a_2=21-2(2)^2\\\\a_2=13[/tex]
[tex]a_3=21-2(3)^2\\\\a_3=3[/tex]
[tex]a_4=21-2(4)^2\\\\a_4=-11[/tex]
[tex]a_5=21-2(5)^2\\\\a_5=-29[/tex]
Therefore, the first five terms of the sequence defined by the explicit formula [tex]a_n=21-2n^2[/tex] are 19, 13, 3, -11, -29.
