Question

The temperature of a chemical reaction ranges between −10 degrees Celsius and 50 degrees Celsius. The temperature is at its lowest point when t = 0, and the reaction completes 1 cycle during a 6-hour period. What is a cosine function that models this reaction?

Answer 1

f(t) = −30 cos pi over 3t + 20
f(t) = −60 cos pi over 3t + 30
f(t) = 30 cos 6t + 20
f(t) = 60 cos 6t + 30

Answer 2

@Directrix @phi @mathmale

Answer 3

Its "A" right?

Answer 4

hmmm what did you get for the amplitude?

Answer 5

-30

Answer 6

well, is 30, but negative in this case
anyhow, to make it short
starts off at -10, goes up to 50, its midline is above the x-axis by 20units, so +20
anyway, yes, it'd be \(y=-30cos\left( \cfrac{\pi }{3}t \right)+20\)

Answer 7

thanks

Answer 8

yw