Problem with writing this function

I do not understand what is wrong with this function. When I try to run the function written like this the error down below comes up.

y = (x.-1)/((x.^2).+x)

Answer 1

[Jon]

You may have some other issues also, but assuming that you have defined x as a column or row vector and you are expecting to calculate y for each element of x you should use something like

y = (x -1)./(x.^2 + x)

Note that the . operator is needed to get element by element division as in ./ and element by element exponentiation as in x.^2

The . operator is not needed and in fact is not a recognized operation for addition and subtraction which is always performed element by element in MATLAB

Answer 2

[Vikas Kumar]

Agree with Jon. I think you are getting error because of . operator you use with the addition and subtraction. This . operator is only meaningful when you want to do element by element operation, which in case of addition and subtraction is by default.

So:

y = (x-1)./((x.^2)+x)

[Jon]

Note also that parenthesis around exponentiation are not necessary either. They do not cause an error, but make the expression harder to read.