Yahoo Answers is shutting down on May 4th, 2021 (Eastern Time) and the Yahoo Answers website is now in read-only mode. There will be no changes to other Yahoo properties or services, or your Yahoo account. You can find more information about the Yahoo Answers shutdown and how to download your data on this help page.
Trending News
Which polynomial function best models the set of data below?? 2 QUESTIONS ONLY! HELP ASAP PLEASE!!!?
1: Which polynomial function best models the set of data below??
X= 0, 2, 4, 6, 8, 10, 12, 14, 16, 18, 20
f(x)= 2, 5, 5, 4, 2, 0, -2, -2, 0, 5, 14
ANSWERS:
y=0.2x^3-0.4x^2+2.2x=2.0
y=2x^3-40x^2+217x+199
y=0.02x+0.40x^2+2.17x+1.99
y=0.02x-0.40x^2+2.17x+1.99
AND
2: Which polynomial function best models the set of data below??
X= -3, -2, -1, 0, 1, 2, 3, 4, 5, 6, 7
f(x)= -60, -10, 10, 15, 10, 0, -5, 0, 15, 50, 100
ANSWERS:
y=0.9x^3+4.9x^2+0.5x+14.4
y=0.9x^3-4.9x^2+0.5x+14.4
y=1.0x^3-4.9x^2-0.9x+17.5
y=0.9x^3-4.8x^2+1.2x+15.0
1 Answer
- roderick_youngLv 77 years ago
I might guess intuitively which function to pick, but if this is homework, they probably want a rigorous explanation of your choice.
What you want to do is plug each x-value of 0, 2, 4, etc. into each polynomial, and compare what you get with the f(x) result supplied. What you do is take the difference, and square it. Add all the squared differences for a given polynomial together, as a measure of how well the polynomial fits the data. The smaller the sum, the better the bit.
It will be tedious to do all the calculations by hand, but perhaps you have a computer program that plots polynomials, or a graphing calculator, or can use a web page to graph polynomials. Even Excel or Openoffice Calc could be used to compute the result.
If this is a lower-level class, possibly could just eyeball the graph and decide which fits best. Or maybe just pick a few points, maybe the ends and the middle, to see how the values line up. If you plug 0 into the first 4 polynomial, you'll immediately see that 2 of them are way off.
