The temperature of a substance during an experiment can be modeled by the function f(x)=−7.5cos(πx30)+31.4 , where f(x) is the temperature °c and x is the number of minutes into the experiment. what is the greatest temperature the substance reached during the experiment?

Answer :  

Explanation :

It is given that,

The temperature of a substance during an experiment is given by a function as :

................(1)

Where,

f(x) is the temperature

and x is the time.

So, for getting a maximum temperature the substance reached during the experiment the value of should by minimum.

We know that the value of cos is minimum at .

So,

We get, x = 30

Put the value of x in equation (1)

Since,

So, the greatest value of temperature the substance reached during the experiment is .

i think it's 35 meters