It should work, since addition is commutative. Maybe you missed something else?

does anyone can explain me why "(curr * curr) + prev" doesn't work? it was my first attempt

https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/Reduce

Here is an step-by-step explanation:
https://medium.com/@trent.dang/javascript-array-reduce-step-by-step-explained-part-1-17926f8e71d5

Do you have a good recource to teach in depth how the reduce method works?
I find the documentation to be a little vague and difficult to understand.