Post by velsd on Dec 6, 2021 19:33:38 GMT
Hello,
I have an issue with the suggested exercise on page 77.
I tried to calculate an example with matlab, and came up with
so, ok , the series (t) matches the straight calculation (r).
But
1.
I have to use a minus sign on the sin; which I can more or less justify in the attached document
2.
I have to do
bigX = k – x;
instead of
bigX = x - k ;
as in the book
regards, Danny.
I have an issue with the suggested exercise on page 77.
I tried to calculate an example with matlab, and came up with
syms n x k
n = 49;
x = 1.05;
k = 0.5;
phi = atan(-1 / k);
sq = sqrt(1 + (k^2));
bigX = k - x;
t = 0;
for j=0:n
y = vpa((bigX^j) * -sin((j + 1) * phi) / (sq^(j+1)));
t = vpa(t + y);
end
disp('t=')
disp(t)
disp('r=')
disp(1 / (1 + (x^2)))
n = 49;
x = 1.05;
k = 0.5;
phi = atan(-1 / k);
sq = sqrt(1 + (k^2));
bigX = k - x;
t = 0;
for j=0:n
y = vpa((bigX^j) * -sin((j + 1) * phi) / (sq^(j+1)));
t = vpa(t + y);
end
disp('t=')
disp(t)
disp('r=')
disp(1 / (1 + (x^2)))
which results in
t=
0.47562425683709879178746666363052
r=
0.4756
t=
0.47562425683709879178746666363052
r=
0.4756
so, ok , the series (t) matches the straight calculation (r).
But
1.
I have to use a minus sign on the sin; which I can more or less justify in the attached document
2.
I have to do
bigX = k – x;
instead of
bigX = x - k ;
as in the book
Could you perhaps point out to me where I have misunderstood something?
As the calculation seems to be correct, but does not equal the text in the book...
regards, Danny.
