2/x +x 3 -2 = 2x -1 +x 3 -2. The first one isn't polynomial as it has a negative exponent and all exponents in a polynomial must be positive. To illustrate why the second one isn't a polynomial rewrite it a little.
The duration of an asthma attack can vary, depending on what caused it and how long the airways have been inflamed. Mild episodes may last only a few minutes; more severe ones can last from hours to days.Mild attacks can resolve spontaneously or may require medication, typically a quick-acting inhaler.More severe attacks can be shortened with appropriate treatment.ild episodes may last only a few minutes; more severe ones can last from hours to days. Mild attacks can resolve spontaneously or may require medication, typically a quick-acting inhaler. More severe attacks can be shortened with appropriate treatment.
Signs and Symptoms. Most people with asthma go for periods of time without any symptoms, then have an asthma attack. Some people have chronic shortness of breath that gets worse during an attack. Asthma attacks can last minutes to days, and can become dangerous if airflow to the lungs becomes severely restricted.Primary symptoms include: 1  Shortness of breath. 2  Wheezing, which usually begins suddenly.ome people have chronic shortness of breath that gets worse during an attack. Asthma attacks can last minutes to days, and can become dangerous if airflow to the lungs becomes severely restricted. Primary symptoms include: 1  Shortness of breath. 2  Wheezing, which usually begins suddenly.