We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.

W(t) models the daily water level  at a pond in Arizona, t days after the hottest day of the year. Here, t is entered in radians.

W(t) = 15cos( 2π/ 3652 t)+43

What is the first time after the hottest day of the year that the water level is 30 cm

 Jan 28, 2019
edited by kikidylm  Jan 28, 2019

I think the function might be


y =15 cos [ (2pi/365) t ] + 43


The water level is at a max at day 0  =  58 cm


The water level is at 30 cm about 153 days after this



I used x for t   here :




cool cool cool 

 Jan 28, 2019

15 Online Users