Question

Find an equation for the nth term of the arithmetic sequence.

-20, -16, -12, -8, ...

Answer 1

Looks like an arithmetic series.

Answer 2

\[
a_n = a_1 + (n-1)d
\]

Answer 3

Like this: an = -20 + 4(n - 1)

Answer 4

That looks right. Test it with \(n=3\)

Answer 5

We know \(n=3 \implies a_n=-12\)

Answer 6

don't you mean -16



























/

Answer 7

No, \(-12\) is the third number in the series.

Answer 8

Okay, you're right. Do mind helping me with one more question?

Answer 9

If I have time.

Answer 10

A certain species of tree grows an average of 0.5 cm per week. Write an equation for the sequence that represents the weekly height of this tree in centimeters if the measurements begin when the tree is 800 centimeters tall

Answer 11

In this case \(a_1 = 800\) and \(d = 0.5\)

Answer 12

I know that's the formula, but for this it's quite difficult for me to input it.