Update computer-science/algorithms/powers.md

computer-science/algorithms/powers.md

@@ -5,7 +5,7 @@
 1. The base case $$n = 0$$, and $$x^0 = 1$$
 2. If $$n$$ is positive compute recursively $$y=x^{(n/2)}$$
 3. If $$n$$ is positive and odd, recursively compute $$x^{(n - 1)}$$
-4. If $$n$$ is 
+4. If $$n$$ is negative, compute $$x^{-n}$$ until n is positive. Then $$x^n = 1/x^{-n}$$
 
 ## Implementation