please I need a really simple JavaScript code "in detail" for Quadratic spline interpolation... I have to save it as HTML file then run it in a browser to get the output

build the quadratic spline interpolation piecewise continuous and differentiable set of quadratic polynomials that go through those points and evaluate the function at x=1.5. Define the data points like this: p = [[0,3.8414709848078967],[0.6931471805599453,6.6818861490654635],[1.0986122886681098,7.5355691627323065],[1.3862943611198906,7.788374949171635],[1.6094379124341003,8.478827375073264],[1.791759469228055,9.887622378713294],[1.9459101490553132,11.440627194940042],[2.0794415416798357,12.307124413342725]] Connect the first two points with a straight line. Then use the ending point and slope together with the following point to build the quadratic equation using the attached Cramer's Rule function. Keep repeating this until your last interval includes the value x. Use the that quadratic function to calculate the value of y.

Cramer's function

{ y = -5x2 -2x -6 } is (0,-6),-2,(1,-13) is { y = -5x2 -2x -6 } { y = -5x2 -2x -3 } is (0,-3),-2,(1,-10) is { y = -5x2 -2x -3 } { y = -5x2 -2x } is (0,0),-2,(1,-7) is { y = -5x2 -2x } { y = -5x2 -2x +3 } is (0,3),-2,(1,-4) is { y = -5x2 -2x +3 } { y = -5x2 -6 } is (0,-6),0,(1,-11) is { y = -5x2 -6 } { y = -5x2 -3 } is (0,-3),0,(1,-8) is { y = -5x2 -3 } { y = -5x2 } is (0,0),0,(1,-5) is { y = -5x2 } { y = -5x2 +3 } is (0,3),0,(1,-2) is { y = -5x2 +3 } { y = -5x2 +2x -6 } is (0,-6),2,(1,-9) is { y = -5x2 +2x -6 } { y = -5x2 +2x -3 } is (0,-3),2,(1,-6) is { y = -5x2 +2x -3 } { y = -5x2 +2x } is (0,0),2,(1,-3) is { y = -5x2 +2x } { y = -5x2 +2x +3 } is (0,3),2,(1,0) is { y = -5x2 +2x +3 } { y = -2x -6 } is (0,-6),-2,(1,-8) is { y = -2x -6 } { y = -2x -3 } is (0,-3),-2,(1,-5) is { y = -2x -3 } { y = -2x } is (0,0),-2,(1,-2) is { y = -2x } { y = -2x +3 } is (0,3),-2,(1,1) is { y = -2x +3 } { y = -6 } is (0,-6),0,(1,-6) is { y = -6 } { y = -3 } is (0,-3),0,(1,-3) is { y = -3 } { y = 0 } is (0,0),0,(1,0) is { y = 0 } { y = 3 } is (0,3),0,(1,3) is { y = 3 } { y = 2x -6 } is (0,-6),2,(1,-4) is { y = 2x -6 } { y = 2x -3 } is (0,-3),2,(1,-1) is { y = 2x -3 } { y = 2x } is (0,0),2,(1,2) is { y = 2x } { y = 2x +3 } is (0,3),2,(1,5) is { y = 2x +3 } { y = 5x2 -2x -6 } is (0,-6),-2,(1,-3) is { y = 5x2 -2x -6 } { y = 5x2 -2x -3 } is (0,-3),-2,(1,0) is { y = 5x2 -2x -3 } { y = 5x2 -2x } is (0,0),-2,(1,3) is { y = 5x2 -2x } { y = 5x2 -2x +3 } is (0,3),-2,(1,6) is { y = 5x2 -2x +3 } { y = 5x2 -6 } is (0,-6),0,(1,-1) is { y = 5x2 -6 } { y = 5x2 -3 } is (0,-3),0,(1,2) is { y = 5x2 -3 } { y = 5x2 } is (0,0),0,(1,5) is { y = 5x2 } { y = 5x2 +3 } is (0,3),0,(1,8) is { y = 5x2 +3 } { y = 5x2 +2x -6 } is (0,-6),2,(1,1) is { y = 5x2 +2x -6 } { y = 5x2 +2x -3 } is (0,-3),2,(1,4) is { y = 5x2 +2x -3 } { y = 5x2 +2x } is (0,0),2,(1,7) is { y = 5x2 +2x } { y = 5x2 +2x +3 } is (0,3),2,(1,10) is { y = 5x2 +2x +3 } { y = 4.9375x2 -20x } : (-4, 159) (-3, 104.4375) (-2, 59.75) (-1, 24.9375) (0, 0) (1, -15.0625) (2, -20.25) (3, -15.5625) (4, -1) (5, 23.4375) (6, 57.75) (7, 101.9375)