Question

Maria started observing Elasticman's height at midnight. At 3 AM, he was at his shortest: only 2 feet tall. At 9 AM, he was at his tallest: 12 feet tall. Elasticman's height is a sinusoidal function of time. In the 24 hours after Maria began observing Elasticman, how much of the time will Elasticman be less than 6 feet tall? (Round your answer to two decimal places.)

___ hr

Answer 1

Please see image and try to understand thanks

please also check calculation twice or thrice and understand the concept