The temperature of a liquid during an experiment can be modeled by the function f(x)=3.8cos(πx20)+2.2 , where f(x) is the temperature in °C and x is the number of minutes into the experiment.

What is the lowest temperature the liquid reached during the experiment?

Round to the nearest tenth of a degree if needed.

Use 3.14 for π .

I think it is -1.6

jjennylove Jan 14, 2019

#1**+3 **

The amplitude of the cos wave will be 3.8 and it will be shifted UP 2.2

Max will be 3.8 + 2.2 = 6 C

Min will be -3.8 + 2.2 = -1.6 C as you found!

Note: this assumes the expiriment runs through at least ONE half period of the wave starting at t=0 !

( Period of wave = 2pi/(20pi) = 1/10 of a minute=6 seconds..... 1/2 period = 3 seconds)

ElectricPavlov Jan 14, 2019

#2**+1 **

Thank you I wanted to double check with someone and your explanatation has helped with that .

jjennylove
Jan 14, 2019