fix(curriculum): clarify RangeError example in debugging lecture (#63964)

curriculum/challenges/english/blocks/lecture-debugging-techniques/6733aa9b006d29f4d11307a5.md

@@ -50,14 +50,14 @@ This example will result in a `developerObj.map is not a function` error because
 
 The last common error we will look at is the `RangeError`.
 
-A `RangeError` happens when your code tries to use a value that’s outside the range of what JavaScript can handle. Here is an example of trying to assign an invalid index to the length of the array:
+A `RangeError` happens when your code tries to use a value that’s outside the range of what JavaScript can handle. Here is an example of assigning an invalid value to an array's length:
 
 ```js
 const arr = [];
 arr.length = -1; 
 ```
 
-Since `-1` is not a valid index used for arrays, this will result in a `RangeError`.
+Since an array's `length` has to be a non-negative integer, setting it to `-1` triggers a `RangeError`.
 
 As you continue to program in JavaScript, just be aware of these different types of errors you will probably encounter and why they are happening.
 
@@ -137,7 +137,7 @@ The error happens because the variable is being treated like a function when it'
 
 ## --text--
 
-Which error occurs when you try to access an array index that doesn't exist?
+Which error occurs when you assign an invalid value, such as `-1`, to an array's `length`?
 
 ## --answers--