inquiry about a command

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mohamed
mohamed on 4 Dec 2013
Edited: Andrei Bobrov on 5 Dec 2013
im trying to answer this question
Write a program to calculate: X = 1/a – 1/2a + 1/3a – 1/4a + ………… – 1/100a For values of a = -5, -3, -1, 1, 3, …50
so far ive tried
a=[-5:2:50];
>> n=[1:100];
>> x=0;
>> for i=1:100
term= (-1.^n +1)/a*n;
x=x+term;
end
but i keeps giving me error (Error using /)
the next question is
Without using loops, generate the vector x = [1 1/2 1/3 1/4 1/5 1/6 … 1/100].
and ive tried putting
n=[2:99]
x=[1/1 :1/n :1/100]
is that right
thx

Answers (2)

Walter Roberson
Walter Roberson on 4 Dec 2013
See the ./ (rdivide) operator and the .* (times) operator
  2 Comments
mohamed
mohamed on 4 Dec 2013
what about it
Walter Roberson
Walter Roberson on 4 Dec 2013
You used the / operator. That is the wrong operator for your purpose. Use ./ instead.

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Andrei Bobrov
Andrei Bobrov on 4 Dec 2013
Edited: Andrei Bobrov on 5 Dec 2013
a=-5:2:50;
n=1:100;
X = -sum((-1).^n./n)*a; % EDIT

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