# Thread: formulate a function of the given points.

1. ## formulate a function of the given points.

hi guys..good day..i find it hard to formulate a function whose points are ...,(-1.5,1), (-1,0), (-.5,1), (0,0), (.5,1), (1,0), (1.5, 1),... where the graph of this function looks like a saw. thanks.

2. ## Re: formulate a function of the given points.

Since you have 7 points, I expect that they will fit a polynomial of order 6 exactly.

So define your function as \displaystyle \begin{align*} f(x) = a\,x^6 + b\,x^5 + c\,x^4 + d\,x^3 + e\,x^2 + f\,x + g \end{align*}. When you substitute in each of the points, you will get 7 equations in 7 unknowns which can be solved simultaneously for a,b,c,d,e,f,g. I would advise using technology such as a CAS to do this