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.
Your doctor will do a physical exam to check for typical signs and symptoms of lupus, including: 1  sun sensitivity rashes, such as a malar or butterfly rash. 2  mucous membrane ulcers, which may occur in the mouth or nose.  arthritis, which is swelling or tenderness of the small joints of the hands, feet, knees, and wrists.