Summation Problem With Error

Find ∑(xi+i)2 for i=4 to 163

xi represents the 'i'th value in the list of x values.

This is what I have coded...

x=0;

for i=4:163;

x=(x+x(i)).^2;

end

x

But it says this:

Index exceeds the number of array elements (1).

Error in (line 31)

x=(x+x(i)).^2;

Answer 1

[madhan ravi]

x is only defined as a scalar value which is zero so when you try to acess 2nd element it gives an error. Cumsum/symsum is recommended for your case.

[Sarah Baki-Hashemi]

I'm not familiar with those functions. I have just been trying to use many simplier functions to obtain the answer.

Answer 2

[Walter Roberson]

i = 4:163;

sum( (i+x(i)).^2)

This expects x to already have been defined

[Torsten]

I think you mean "i" instead of "ii".

[Walter Roberson]

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