Fixed typo in Book 3 Chapter 3.6, fixes #1744

books/RayTracingTheRestOfYourLife.html

@@ -1093,7 +1093,7 @@
 This says _a random variable plucked from our PDF has a 25% chance of being 1 or lower_. We want a
 function $f(d)$ that takes a uniform distribution between 0 and 1 (_i.e_ `f(random_double())`), and
 returns a random value according to a distribution that has the CDF $P(x) = \frac{x^2}{4}$. We don’t
-know yet know what the function $f(d)$ is analytically, but we do know that 25% of what it returns
+know yet what the function $f(d)$ is analytically, but we do know that 25% of what it returns
 should be less than 1.0, and 75% should be above 1.0. Likewise, we know that 50% of what it returns
 should be less than $\sqrt{2}$, and 50% should be above $\sqrt{2}$. If $f(d)$ monotonically
 increases, then we would expect $f(0.25) = 1.0$ and $f(0.5) = \sqrt{2}$. This can be generalized to