a(i)=(100.*(((x(i+1)-x(i).^2)).^2)+(x(i)-1).^2);

It seems like you've provided a MATLAB code snippet and are likely looking for an explanation or a specific question related to it. The code snippet defines a vector a based on the elements of another vector x. Here's a breakdown of the code:

a(i) = (100 * (((x(i+1) - x(i)^2)^2) + (x(i) - 1)^2));

1. x(i): This represents the i-th element of the vector x.
2. x(i+1): This represents the (i+1)-th element of the vector x.
3. x(i)^2: This squares the i-th element of x.
4. x(i+1) - x(i)^2: This calculates the difference between the (i+1)-th element and the square of the i-th element.
5. 100 * (((x(i+1) - x(i)^2)^2): This scales the squared difference by a factor of 100.
6. (x(i) - 1)^2: This squares the difference between the i-th element of x and 1.
7. (100 * (((x(i+1) - x(i)^2)^2) + (x(i) - 1)^2): This adds the scaled squared difference to the squared difference of the i-th element and 1.

The code is likely part of a larger script that is computing a sequence of values for a based on corresponding values in x. It's important to note that this code assumes that x is a vector with at least i+1 elements to avoid indexing errors.

If you have a specific question about this code or its context, please provide more details, and I'll be happy to assist you further.