the mass in grams of a melting ice block is given by the formula M= 5-(t^2) where t is the time in minutes. Show that the rate at which the ice block is melting is given by R= -2t g min^-1 and find the rate at which it is melting after 2 minutes

Question

anonymous · Answer

differentiate it ... it gives ..... rate 
therefore rate=2t
after 2 min its 4 g/min

anonymous · Answer

did you get this ?

anonymous · Answer

i thought that when you differentiate, you would get -2t

anonymous · Answer

yea its -2t sorry typo :D

anonymous · Answer

but how come the answer is +4 then?

anonymous · Answer

see the negative sign denotes that the quantity is decreasing !!