A regression with two or more predictor variables is called a multiple. regression. (When we need to note the difference, a regression on a single predic-. tor is called a simple regression.) Weâd never try to find a regression by hand, and. even calculators arenât really up to the task.
Different jurisdictions have different definitions of what constitutes a prescription drug. Rx is often used as a short form for prescription drug in North America-a contraction of the Latin word  recipe  (an imperative form of recipere) meaning take.
From Wikipedia, the free encyclopedia. A prescription drug (also prescription medication or prescription medicine) is a pharmaceutical drug that legally requires a medical prescription to be dispensed. In contrast, over-the-counter drugs can be obtained without a prescription.The reason for this difference in substance control is the potential scope of misuse, from drug abuse to practicing medicine without a license and without sufficient education.he safety and effectiveness of prescription drugs in the US is regulated by the federal Prescription Drug Marketing Act of 1987. The Food and Drug Administration (FDA) is charged with implementing this law.