posted by Erica on .
the design below grows each day, as shown. if the pattern continues to grow like this, how many tiles will there be in the design on the tenth day? on the fiftieth day?
Day 1 1 tile
Day 2 5 tiles
Day 3 13 tiles
1+4(n-1) where n is the day number
on day 10
on day fifty
Day 3 does not fit: 1+4*2 = 9
Since the difference is changing by 4 each day, we will have a quadratic:
Day n: 2n^2 - 2n + 1
What do you mean by the ^ in your equation Steve? I don't really understand the 2n^2-2n+1. I did figure out it was a quadratic equation, and actually happened to figure out the entire problem until I noticed it said "Write a description or formula that allows me to figure out the number of tiles for any day number?"
Oh, ok, do you mean to cube the first number by the 2nd, get back to me... Thnx
Steve is wrong!!! D: