Textbook Problem

Checkpoint 6 Worked-out solution available at Larson Applied Calculus.com

The amount G (in trillion Btu) of natural gas consumed by the commercial sector in the United States during 2013 can be modeled by

$G\text{ = 320}\text{.033 + 214}\text{.203 sin}\left(\text{0}\text{.436}t\text{+ 1}\text{.613}\right)$ where t is the time (in months), with t = 1 corresponding to January. Graph the model using a graphing utility. In 2013, did the amount of natural gas consumed by the commercial sector exceed 350 trillion Btu? If so, during which months? (Source: U.S. Energy Information Administration)