Question

In Lecture 3 - Problem Solving, the square root program that uses bi-section search algorithm doesn't enter the while loop for the value 4, instead it skips the loop and spits out the square root as 2.0 directly. Number of guesses = 0. Why is that?

Answer 1

Haha, figured out. Because it doesn't satisfy the conditions of the while loop. Before the loop begins we initialized ans to (high + low)/2.0 which equals 2.0, and the condition of the while loop first checks for ans^2 - x, which is 2^2 - 4 = 0. Since 0 is less than epsilon, the program doesn't enter the loop.

Answer 2

The code, if anyone wants to check.