$x[7]=\{-2,-1,0,1,2,3,4\}$

$y[7]=\{0\mathrm{.}6,-4\mathrm{.}6,-6\mathrm{.}0,-3\mathrm{.}4,1\mathrm{.}2,11\mathrm{.}7,15\mathrm{.}9\}$

or

You want to fit the data with two different regression curves, i$.$e$,$ in the form of

$y=a_1{x}^2+b_1,$

$or$

$y=a_{2}x+b_2,$

Write a $C$ code to determine $a_1,b_1,a_2,b_2$ for $x[7]$ and $y[7].$

Plot the data points and two curves together like the graph above with GNUplot.