Right-B[I]CEP: Checking Inverse Relationships

Sometimes you’ll be able to check behavior by applying its logical inverse. For mathematic computations, this is often the case: you can verify division with multiplication, addition with subtraction, and so on.

We decided to implement our own square-root function using Newton’s algorithm (a silly idea, given that Math.sqrt() is a trustworthy native implementation; apparently, we suffer from not-invented-here syndrome). We recall that if we derive the square root of a number and square that result (that is, multiply it by itself), we should get the same number we started with:

iloveyouboss/15/test/scratch/NewtonTest.java
 
import​ org.junit.*;
 
import​ static org.junit.Assert.*;
 
import​ static ...

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