It could be said that mathematics is the language of physics. That is another way of better understanding what is physics. Numerical values, units of measurement, and similar concepts are all mathematical in nature, and are used to describe physical quantities in the most accurate and precise manner.
In brief: Cough headache. There are a couple of possibilities. Coughing can raise the pressure inside your head, which can cause pain sometimes. There is also a poorly-understood entity called the primary cough headache,  that is associated with coughing, straining, laughing, crying, etc.
To find out what's causing your cough your GP might: take a sample of any mucus you might be coughing up; order an X-ray, allergy test, or test to see how well your lungs work; refer you to hospital to see a specialist, but this is very rare; What causes coughs. Most coughs are caused by cold or flu. Other causes include: smoking; heartburn (acid reflux)