Suppose that the monthly average temperature in Argentina is to be modelled by the trig function=cos((+))+

y=Acos(B(t+C))+D, where,,,

A,B,C,Dare constants,

yis the monthly average temperature in degree celsius and

tis the month,011

0t11, where=0

t=0is January and=11

t=11is December. The warmest month of the year is February (=1

t=1) with an average temperature of 19.9

C. The coldest month is August (=7

t=7) with an average temperature of 8.5

C. Determine the cosine function that fits the data.