Update faq.md

Author: pulkitkrishna00

docs/faq.md

@@ -3,5 +3,7 @@
 Each curriculum has its own FAQ. Here is a list of them:
 
 - [Computer Science FAQ](../computer-science/faq)
+- [Math FAQ](../math/faq)
+- [Pre-College Math FAQ](../precollege-math/faq)
 
 Some Course pages also have their own course specific FAQ. Visit them to read their FAQs.