From 1970 to 1990, the average cost (C) of a
new car (in dollars) can be approximated by
the model C = 33.4t2 + 4309 where (t) is the year, with t=0 corresponding to1970. During which year was the average cost of a new car $15,000?

Question

From 1970 to 1990, the average cost (C) of a
new car (in dollars) can be approximated by
the model C = 33.4t2 + 4309 where (t) is the year, with t=0 corresponding to1970. During which year was the average cost of a new car $15,000?

anonymous · Answer

t2 = t squared?

anonymous · Answer

yes

anonymous · Answer

Well, here's what I came up with....
C = 33.4t2 + 4309 
15000 = 33.4t2 + 4309 
10691 = 33.4t2
t2 = 320.0898203592814
t = 17.89105419921592

anonymous · Answer

thank you !!! :)

anonymous · Answer

You're welcome! I hope it's right... :)

anonymous · Answer

its not :(

anonymous · Answer

Yep... Just what I was about to type: "Thought I'm pretty certain that's not the real answer"... I'm truly sorry!

anonymous · Answer

its okay , now worries

anonymous · Answer

What is the correct answer, if I may ask?

anonymous · Answer

it doesnt tell me, its an online homework, everytime i get it wrong it just takes points away i get 6 trys

anonymous · Answer

Wow! I'm really really sorry I made you lose points! Shame on me :(

anonymous · Answer

its okay lol :))