Product Rule. If the two functions f(x) and g(x) are differentiable (i.e. the derivative exist) then the product is differentiable and, The proof of the Product Rule is shown in the Proof of Various Derivative Formulas section of the Extras chapter.
Inflammation is the most common reason for muscle pain and aches. Any time that major inflammation exists (strep throat, hepatitis, cancer, lupus, acute heart attack, etc.), signs and symptoms often include fevers, sweats, chills, fatigue, weight loss, and various muscle aches, pains and weakness.
It is not uncommon for people with lupus to experience muscle aches and pain (myalgias) or have inflammation of certain muscle groups (myositis), which causes weakness and loss of strength. More than 90 percent of people with lupus will experience joint and/or muscle pain at some time during the course of their illness.uscle pain and muscle tenderness, especially during periods of increased disease activity (flare), occur in as many as 50 percent of those with lupus. The symptoms may have different causes. It is important for your physician to determine the cause of your symptoms since treatments are quite varied.