X

J1(x)

1.8

0.5815

-2

-637

2.0

0.5767

generate the third-order Newton's interpolating polynomial. Use the newtintr function to

interpolate at x = 2.1. Validate your answer using Matlab's polyfit and polyval functions.

-1

-96.5

2.2

0.5560

2. Ohm's law states that the voltage, resistance and current in a resistor are related by the

linear equation V=RI. In practice, however, real resistors may not always obey this law.

Suppose that you performed a precise experiment in the lab and obtained the following

data for the resistor.

-0.5

-20.5

2.4

0.5202

0.5

20.5

1

96.5

2

637

Use a fifth-order polynomial to fit the data and compute V for 1 = 0.1. Employ function

newtintr. Next, use Matlab's polyfit to generate the interpolation polynomial. Plot the data

points and the polynomial, on the same graph, for x-axis limits [-2.2 2.2].

1

3. Consider the function f(x) =

1+25x2

Generate five equidistantly spaced points

(xi, f (xi)) over the interval: [-1 1]. Fit this data with (a) a fourth-order polynomial, (b) a

linear spline and (c) a cubic spline. Assume spline derivatives are zero at the end points.

Compare your results graphically (use the x-axis range [-1 1]).