MATLAB: E^x/x

expplotplottingSymbolic Math Toolboxtaylor series

how can i plot e^x/x code
syms x;
f=exp(x)/x
t3=taylor(f, 'order',4) ;
xd=-pi:pi/20:pi;
yd=subs(f,x,xd);
td3=subs(t3,x,xd);
plot(xd,yd);
error
Error using symengine
Cannot compute a Taylor expansion of the input.
Error in sym/taylor (line 128)
tSym = mupadmex('symobj::taylor',f.s,x.s,a.s,options);
Error in exp1 (line 3)
t3=taylor(f, 'order',4) ;

Best Answer

function plot doesn't work with input type syms
Instead try the following
x=[-10:0.0001:10];
y=exp(x)./x;
plot(x,y);
axis([-10 10 -1e3 1e3])
grid on
title('e^x/x')
and the following doesn't crash
syms x x0;
  y= exp(x-x0)/(x-x0)
  x_tay4=taylor(y, 'order',4)
  y =
  exp(x - x0)/(x - x0)
  x_tay4 =
  (- exp(-x0)/(6*x0) - exp(-x0)/(2*x0^2) - exp(-x0)/x0^3 - exp(-x0)/x0^4)*x^3 + (- exp(-x0)/(2*x0) - exp(-x0)/x0^2 - exp(-x0)/x0^3)*x^2 + (- exp(-x0)/x0 - exp(-x0)/x0^2)*x - exp(-x0)/x0
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thanks in advance for time and attention
John BG
<mailto:jgb2012@sky.com jgb2012@sky.com>
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