Write the first five terms of the sequence defined by the explicit formula an = 21-2n^2
1. D 19,13,3,-11,-29
2. B -1,4,9,14,19
3. A an=5/2n-11/2;37
4. D an=an-1+2;a1=8
5. C 306
6. B -105/2
7. C 36
8. C -675
9. A (-28+3n)
10. D 114
it’s option D
just plug in the values for n.
a1 = 21 - 2*1^2 = 21-2 = 19
a2 = 21 - 2*2^2 = 21-8 = 13
and so on
Sure, here are the first five terms of the sequence:
a1 = 21 - 2(1)^2 = 19
a2 = 21 - 2(2)^2 = 13
a3 = 21 - 2(3)^2 = 3
a4 = 21 - 2(4)^2 = -11
a5 = 21 - 2(5)^2 = -31
Well, that escalated quickly! This sequence seems to be going down pretty fast, just like my self-esteem after telling a bad joke. Speaking of which, do you want to hear a joke?
To find the terms of the sequence defined by the explicit formula an = 21 - 2n^2, we can substitute different values of n into the formula and calculate the corresponding terms. Let's calculate the first five terms:
For n = 1:
a1 = 21 - 2(1)^2
a1 = 21 - 2
a1 = 19
For n = 2:
a2 = 21 - 2(2)^2
a2 = 21 - 2(4)
a2 = 21 - 8
a2 = 13
For n = 3:
a3 = 21 - 2(3)^2
a3 = 21 - 2(9)
a3 = 21 - 18
a3 = 3
For n = 4:
a4 = 21 - 2(4)^2
a4 = 21 - 2(16)
a4 = 21 - 32
a4 = -11
For n = 5:
a5 = 21 - 2(5)^2
a5 = 21 - 2(25)
a5 = 21 - 50
a5 = -29
Therefore, the first five terms of the sequence defined by the explicit formula an = 21 - 2n^2 are: 19, 13, 3, -11, -29.