Write a function called mysum that sums the first n positive numbers. Give the result x1 for n=20,and the result x2 for n=100. For example, if n = 2, mysum computes the sum of 1 and 2. The result is 3.

Question

Juan Gomez 2019-9-4

回答： Devineni Aslesha 2019-9-9

I tried using a for loop setting

mysum = 0;
for k= 1;n
          mysum  = k+n;
end
mysum

Walter Roberson 2019-9-4

Functions start with the key word "function".

MATLAB uses colon between start and end point in a for loop, not semi-colon. k=1:n not k=1;n

Your algorithm is not correct: you are not totalling anything, you overwriting all calculations done so far each iteration of the for loop.

Answer 1

Devineni Aslesha 2019-9-9

Create a function using the keyword ‘function’ and save the file with name mysum.m.

function output = mysum(n)
output = 0;
for k = 1:n
output = output + k;
end
end

To get the sum of first 10 positive numbers, call the function using the below syntax.

output = mysum(10)

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