Great ! Thank you ! <| sep |> If Shining noctowl falls . through I will do it . <| sep |> One thing they left out of the slide . New Egi glamour will also be available for purchase from the Mog Station . More like New Egi glamour will be available with the puchase of the 2018 Fanfest Livestream <| sep |> Right off the bat where you . said dxdt 100 you made a mistake . x 100 ftdxdt 5 ftsYour definition of c was ambiguous , likely helping you make mistakes . the rate at which the spill is increasing . The spill is an object . Might as well say your shoes are increasing . Only quantities increase . or decrease so , you gotta specify whether c ' s the rate of increase of the radius , area , volume , mass , 4 thdimensional hypervolume , or whatever , but you can ' t just treat it like it ' s obvious , ' cause really it ' s not obvious . Then you went and sked for the derivative of the derivative of an ambiguous quantity . dcdt ? If you meant for c to be the rate of increase of the radius of the spill , then that ' s given already c dxdt 5 ftsIf you meant c to be the rate of area increase , well , that ' d be decent , ' cause that ' s what the question asks for . But then you started writing about the derivative of the answer . d ? dt ddt r 2 If that ? is an x , then you reported that radius equals itself squared times pi . If that ? is a c , . then it looks like you ' ve switched from c being a rate of ambiguous quantity increase to c being the value of area not a rate . Okay , I see you subbed in 100 for d ? dt , meaning ? must be x . So you said that the radius x is equal to a multiple of the square of itself . That . That would not be correct . You applied the chain rule correctly so , that ' s nice . But then it looks like you wrote dcdt where drdt should go . Then you substituted the 5 fts figure in place of the radius , which would be a number of feet . Okay , so , you screwed up at almost every single step , but I think just ONE trick will help you sort out ALL the mistakes Focus on units . Don ' t use naked numbers . The answer stipulated by the question is an area ft 2 rate 1 s , having units of ft 2 s , but your answer had units of fts . So , just looking at the units , you can tell your answer was wrong . Near the top , you said dxdt 100 ft . Since x is the radius of the spill , x is in ft . t is time , which is in s . So , dxdt must have units of fts . A speed isn ' t a distance . So you can avoid carrying mistakes forward if you explicitly check your units every time . When you subbed 5 fts in place of r , the radius equal to x , which is a length in ft , you could notice right away that that ' s not a correct substitution on account of the differing unitsEven when you defined c to be some . vague thing , you could catch that problem right away by demanding it of yourself to be able to say what the units of that quantity will be . Your definition said c would be a rate of some sort , which means it should have a unit that has a time denominator somethings