# The root of the problem - Solution

## Enter the function y(t)=t^2-2049

Tap on y(t) in the menu and then on the submenu (⋮) and select 'General'
Enter the function as above and click OK.

## Change the View settings so that the derivative is not shown

Select the View Icon and from the View window turn off the display Derivative switch.

## Change the t-axis

Tap on the settings icon and then the submenu (⋮) and select 't-axis' and change the range to 44 to 46 and tap on OK.

## y(t)=t^2-2049 with 44<=t<46

Tap on the 'Mode' icon and then on the submenu (⋮) and select 'Zero Find'. Change the Accuracy (No. of s.f.) to 14 and tap OK. You will get the message popup "Click on the t-axis" and after tapping OK on this popup then click once on the t-axis in the vicinity of where the graph crosses the t-axis. After performing the zero-finding plotXpose will display the result and the sequence of values found during the calculation. An example output is below, where Newton- has calculated the square root of 2049 as 45.265881191025 to 14 significant figures.

Solving t^2-2049=0: Success. The Newton-Raphson method has converged to the value (45.265881191025,0.00000000000000E+000).
The sequence of values found was
( n, t , y(t))
(0, 44.9651412963867, -2.713606819597771E+001)
(1, 45.2668869088058, 9.105041461407382E-002)
(2, 45.2658812021974, 1.011445874610217E-006)
(3, 45.2658811910251, 0.000000000000000E+000)
(4, 45.2658811910251, 0.000000000000000E+000)
(5, 45.2658811910251, 0.000000000000000E+000)

plotXpose app is available on Google Play