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% Taylor approximation: e^x
% f(x) = e^x = pn(x) + Rn(x)
% Figure1.1 on textbook page 5
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close all
clc
clear
set(0,'DefaultFigureWindowStyle','docked')

x = -1.5:0.01:1.5;    % x
fx = exp(x);         % original exp() from matlab
p2 = myexp(x,2);    % my version of exp() with n =  3
p9 = myexp(x,9);    % my version of exp() with n =  5

figure
plot(x,fx);          % plot fx
hold on             % keep the first plot on
plot(x,p2,':');     % plot y1 in red 
plot(x,p9,'--r');     % plot y2 in green
hold off            
title('exp(t) and its taylor series approximation')  % title of the plot
xlabel('x')              % lable of x axis
ylabel('magnitude')         % lable of y axis
legend('exp(x)','P_2(x)','P_9')
grid on