Chapter 15 - Recursion - Section 15.4 - Problem Solving using Recursion - Check Point - MyProgrammingLab - Page 507: 15.10

The call stack for isPalindrome("abcba") is: The main function calls isPalindrome("abcba"). isPalindrome("abcba") is called with the input string "abcba". The function checks if the length of the string is less than or equal to 1. Since it is not, the function proceeds to the next step. The function checks if the first and last characters of the string are not equal. They are equal, so the function proceeds to the next step. The function calls isPalindrome("bcb"). isPalindrome("bcb") is called with the input string "bcb". The function checks if the length of the string is less than or equal to 1. Since it is not, the function proceeds to the next step. The function checks if the first and last characters of the string are not equal. They are equal, so the function proceeds to the next step. The function calls isPalindrome("c"). isPalindrome("c") is called with the input string "c". The function checks if the length of the string is less than or equal to 1. Since it is, the function returns True. isPalindrome("c") returns True to isPalindrome("bcb"). isPalindrome("bcb") returns True to isPalindrome("abcba"). isPalindrome("abcba") returns True to main. main prints "Is abcba a palindrome? True". The call stack shows how the isPalindrome function is called recursively with a smaller substring until a base case is reached, and then the function returns a value that is used to compute the final result. In this case, the function checks if a string is a palindrome by checking if the first and last characters are equal, and then calling itself with a smaller substring until the base case is reached.

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