The 1918 flu pandemic, commonly referred to as the Spanish flu, was a category 5 influenza pandemic caused by an unusually severe and deadly Influenza A virus strain of subtype H1N1.
Project Lead The Way (PLTW) is an American nonprofit organization that develops STEM curricula for use by US elementary, middle, and high schools.
pw â Piecewise expression or function. symbolic expression | symbolic function. Piecewise expression or function, returned as a symbolic expression or function. The value of pw is the value val of the first condition cond that is true. To find the value of pw, use subs to substitute for variables in pw.