Calculus - rates of change

Hi,

I was just wondering if the way I worked out this question is correct.

Basically I subbed in 4 into the dT/dt equation and then the answer I got from that I added it to -7. Is this correct ?

Thanks

They are asking for the temperature at the end of 4 hours. Subbing 4 into $dT/dt$ will give you the rate at which the temperature is increasing with time.

To get back to an equation involving the temperature, what would you do to the $dT/dt$ equation? A hint is in the spoiler.

So after integrating should I sub in T=-7degrees to get the constant?

Should I then use the temp equation I got from integrating and sub in t=4 to find the temp at the end of 4 hours ?

Yes, you would sub in T = -7 and t = 0 (as the temperature is initally -7 degrees), and then use the equation you got from integrating.

Forget the question! Look at the hyperbolas the pixels on your screen are making