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.
Signs and symptoms may come on suddenly or develop slowly, may be mild or severe, and may be temporary or permanent. Most people with lupus have mild disease characterized by episodes â called flares â when signs and symptoms get worse for a while, then improve or even disappear completely for a time. The signs and symptoms of lupus that you experience will depend on which body systems are affected by the disease. The most common signs and symptoms include: 1  Fatigue and fever. 2  Joint pain, stiffness and swelling.  Butterfly-shaped rash on the face that covers the cheeks and bridge of the nose.