Find a Formula for A_n for the Arithmetic Sequence $a _ { 3 } = 0 , a _ { 9 } = - 12$

question 11

Multiple Choice

Find a formula for a_n for the arithmetic sequence. $a _ { 3 } = 0 , a _ { 9 } = - 12$

• A)a_n = 4 - 2n
• B)a_n = -6 + 4n
• C)a_n = - 2 + 4n
• D)a_n = 6 - 2n
• E)a_n = 4n

---

Definitions:

Alveolar Expansion

The process of air sacs in the lungs enlarging during inhalation, facilitating gas exchange between the lungs and blood.

Lung Recoil

The tendency of the lungs to return to their original size after being stretched or expanded, a critical factor in normal breathing and expelling air from the lungs.

Pleural Pressure

This refers to the pressure within the pleural cavity, which is crucial in the mechanics of breathing.

Thoracic Wall

The part of the anatomy that forms a protective boundary around the thoracic cavity, which contains the lungs and heart; comprises the rib cage, spine, and sternum.