hi every one i need series for erfc(x) match with it in plot

i need correct series for the equation of erfc(x) and maching with it in plot

[Dyuman Joshi]

What do you mean by "correct series"? And for which values do you need the plot?

[sura]

there are series representation. taylor series is series expansion. in wolfarm website you can write series erfc(x). you will find three or more series representation.

i need one of these match with it with function by k not x

[sura]

like this

Answer 1

[Sam Chak]

Hi @sura

Are you looking for something like this?

syms x
sympref('PolynomialDisplayStyle', 'ascend');

f = erfc(x);                    % function
T = taylor(f, 'Order', 8)       % Taylor series

T = 

xd = -2:0.1:2;
yd = subs(f, x, xd);

fplot(T, [-2, 2])
hold on
plot(xd, yd, 'r-.'), grid on
title('Taylor approximation vs. actual function')
legend('Taylor','Function')

[sura]

thanks sam chak but the solution is not i need. there are series representation. taylor series is series expansion. in wolfarm website you can write series erfc(x). you will find three or more series representation.

i need one of these match with it with function by k not x

best regards

[sura]

like this

[Torsten]

If you had studies Sam Chak's answer, you would have seen that your series expansion is just the one that he used for the plot.