Possible Duplicate:
Writing a function $f$ when $x$ and $f(x)$ are known
If I am given 9 co-ordinates of a random graph say for e.g
1. (2,1) 2. (4,3) 3. (7,9) 4. (9,5) 5. (10,3) 6. (11,1) 7. (13,4) 8. (15,7) 9. (17,10)
((this is the plotted graph exactly however it needs to be curved ))
How can i create an equation to approximately fit the graphs trendline curve.